#include<bits/stdc++.h>
using namespace std;

#define rep(i,n) for (int i = 0; i < (int)(n); i++)
#define repp(i,m,n) for (int i = (m); i < (int)(n); i++)
#define reb(i,n) for (int i = (int)(n-1); i >= 0; i--)
#define all(v) (v).begin(),(v).end()
using pii = pair<int,int>;

namespace noya2{

/*　~ (. _________ . /)　*/

}

using namespace noya2;

namespace noya2::internal {

template<class E>
struct csr {
    csr () {}
    csr (int _n) : n(_n) {}
    csr (int _n, int m) : n(_n){
        start.reserve(m);
        elist.reserve(m);
    }
    // ACL style constructor (do not have to call build)
    csr (int _n, const std::vector<std::pair<int,E>> &idx_elem) : n(_n), start(_n + 2), elist(idx_elem.size()) {
        for (auto &[i, e] : idx_elem){
            start[i + 2]++;
        }
        for (int i = 1; i < n; i++){
            start[i + 2] += start[i + 1];
        }
        for (auto &[i, e] : idx_elem){
            elist[start[i + 1]++] = e;
        }
        prepared = true;
    }
    int add(int idx, E elem){
        int eid = start.size();
        start.emplace_back(idx);
        elist.emplace_back(elem);
        return eid;
    }
    void build(){
        if (prepared) return ;
        int m = start.size();
        std::vector<E> nelist(m);
        std::vector<int> nstart(n + 2, 0);
        for (int i = 0; i < m; i++){
            nstart[start[i] + 2]++;
        }
        for (int i = 1; i < n; i++){
            nstart[i + 2] += nstart[i + 1];
        }
        for (int i = 0; i < m; i++){
            nelist[nstart[start[i] + 1]++] = elist[i];
        }
        swap(elist,nelist);
        swap(start,nstart);
        prepared = true;
    }
    const auto operator[](int idx) const {
        return std::ranges::subrange(elist.begin()+start[idx],elist.begin()+start[idx+1]);
    }
    auto operator[](int idx){
        return std::ranges::subrange(elist.begin()+start[idx],elist.begin()+start[idx+1]);
    }
    const auto operator()(int idx, int l, int r) const {
        return std::ranges::subrange(elist.begin()+start[idx]+l,elist.begin()+start[idx]+r);
    }
    auto operator()(int idx, int l, int r){
        return std::ranges::subrange(elist.begin()+start[idx]+l,elist.begin()+start[idx]+r);
    }
    size_t size() const {
        return n;
    }
    int n;
    std::vector<int> start;
    std::vector<E> elist;
    bool prepared = false;
};

} // namespace noya2::internal

namespace noya2 {

struct hld_tree {
    int n, root;
    std::vector<int> down, nxt, sub, tour;
	noya2::internal::csr<int> childs;

    // default constructor (nop)
    hld_tree () {}

    // tree with _n node
    // after construct, call input_edges / input_parents / add_edge _n - 1 times
    hld_tree (int _n, int _root = 0) : n(_n), root(_root), down(n), nxt(n), sub(n, 1), tour(n) {
        if (n == 1){
            nxt[0] = -1;
            down[0] = -1;
            build_from_parents();
        }
    }

    // par[i] < i, par[0] == -1
    hld_tree (const std::vector<int> &par) : n(par.size()), root(0), down(n, -1), nxt(par), sub(n, 1), tour(n){
        build_from_parents();
    }

    // par[i] < i, par[0] == -1
    hld_tree (std::vector<int> &&par) : n(par.size()), root(0), down(n, -1), sub(n, 1), tour(n) {
        nxt.swap(par);
        build_from_parents();
    }

    // distinct unweighted undirected n - 1 edges of tree 
    hld_tree (const std::vector<std::pair<int, int>> &es, int _root = 0) : n(es.size() + 1), root(_root), down(n), nxt(n), sub(n, 1), tour(n) {
        for (auto &[u, v] : es){
            down[u]++;
            down[v]++;
            nxt[u] ^= v;
            nxt[v] ^= u;
        }
        build_from_edges();
    }

    // input parents from cin
    template<int indexed = 1>
    void input_parents(){
        // using std::cin;
        nxt[0] = -1;
        for (int u = 1; u < n; u++){
            cin >> nxt[u];
            nxt[u] -= indexed;
        }
        build_from_parents();
    }

    // input n - 1 edges from cin
    template<int indexed = 1>
    void input_edges(){
        // using std::cin;
        for (int i = 1; i < n; i++){
            int u, v; cin >> u >> v;
            u -= indexed;
            v -= indexed;
            down[u]++;
            down[v]++;
            nxt[u] ^= v;
            nxt[v] ^= u;
        }
        build_from_edges();
    }

    void add_edge(int u, int v){
        down[u]++;
        down[v]++;
        nxt[u] ^= v;
        nxt[v] ^= u;
        // use tour[0] as counter
        if (++tour[0] == n - 1){
            build_from_edges();
        }
    }

    size_t size() const {
        return n;
    }

    // top vertex of heavy path which contains v
    int leader(int v) const {
        return nxt[v] < 0 ? v : nxt[v];
    }

    // level ancestor
    // ret is ancestor of v, dist(ret, v) == d
    // if d > depth(v), return -1
    int la(int v, int d) const {
        while (v != -1){
            int u = leader(v);
            if (down[v] - d >= down[u]){
                v = tour[down[v] - d];
                break;
            }
            d -= down[v] - down[u] + 1;
            v = (u == root ? -1 : ~nxt[u]);
        }
        return v;
    }

    // lowest common ancestor of u and v
    int lca(int u, int v) const {
        int du = down[u], dv = down[v];
        if (du > dv){
            std::swap(du, dv);
            std::swap(u, v);
        }
        if (dv < du + sub[u]){
            return u;
        }
        while (du < dv){
            v = ~nxt[leader(v)];
            dv = down[v];
        }
        return v;
    }

    // distance from u to v
    int dist(int u, int v) const {
        int _dist = 0;
        while (leader(u) != leader(v)){
            if (down[u] > down[v]) std::swap(u, v);
            _dist += down[v] - down[leader(v)] + 1;
            v = ~nxt[leader(v)];
        }
        _dist += std::abs(down[u] - down[v]);
        return _dist;
    }

    // d times move from to its neighbor (direction of to)
    // if d > dist(from, to), return -1
    int jump(int from, int to, int d) const {
        int _from = from, _to = to;
        int dist_from_lca = 0, dist_to_lca = 0;
        while (leader(_from) != leader(_to)){
            if (down[_from] > down[_to]){
                dist_from_lca += down[_from] - down[leader(_from)] + 1;
                _from = ~nxt[leader(_from)];
            }
            else {
                dist_to_lca += down[_to] - down[leader(_to)] + 1;
                _to = ~nxt[leader(_to)];
            }
        }
        if (down[_from] > down[_to]){
            dist_from_lca += down[_from] - down[_to];
        }
        else {
            dist_to_lca += down[_to] - down[_from];
        }
        if (d <= dist_from_lca){
            return la(from, d);
        }
        d -= dist_from_lca;
        if (d <= dist_to_lca){
            return la(to, dist_to_lca - d);
        }
        return -1;
    }

    // parent of v (if v is root, return -1)
    int parent(int v) const {
        if (v == root) return -1;
        return (nxt[v] < 0 ? ~nxt[v] : tour[down[v] - 1]);
    }

    // visiting time in euler tour
    // usage : seg.set(index(v), X[v])
    int index(int vertex) const {
        return down[vertex];
    }
    // usage : seg.set(index_edge(e.u, e.v), e.val)
    int index(int vertex1, int vertex2) const {
        return std::max(down[vertex1], down[vertex2]);
    }

    // subtree size of v
    int subtree_size(int v) const {
        return sub[v];
    }

    // prod in subtree v : seg.prod(subtree_l(v), subtree_r(v))
    int subtree_l(int v) const {
        return down[v];
    }
    int subtree_r(int v) const {
        return down[v] + sub[v];
    }

    // v is in subtree r
    bool is_in_subtree(int r, int v) const {
        return subtree_l(r) <= subtree_l(v) && subtree_r(v) <= subtree_r(r);
    }
    
    // distance table from s
    std::vector<int> dist_table(int s) const {
        std::vector<int> table(n, -1);
        table[s] = 0;
        while (s != root){
            table[parent(s)] = table[s] + 1;
            s = parent(s);
        }
        for (int v : tour){
            if (table[v] == -1){
                table[v] = table[parent(v)] + 1;
            }
        }
        return table;
    }

    // dist, v1, v2
    std::tuple<int, int, int> diameter() const {
        std::vector<int> dep = dist_table(root);
        int v1 = std::ranges::max_element(dep) - dep.begin();
        std::vector<int> fromv1 = dist_table(v1);
        int v2 = std::ranges::max_element(fromv1) - fromv1.begin();
        return {fromv1[v2], v1, v2};
    }

    // vertex array {from, ..., to}
    std::vector<int> path(int from, int to) const {
        int d = dist(from, to);
        std::vector<int> _path(d + 1);
        int front = 0, back = d;
        while (from != to){
            if (down[from] > down[to]){
                _path[front++] = from;
                from = parent(from);
            }
            else {
                _path[back--] = to;
                to = parent(to);
            }
        }
        _path[front] = from;
        return _path;
    }

    // path decomposition and query (vertex weighted)
    // if l < r, decsending order tour[l, r)
    // if l > r, acsending order tour(l, r]
    template<bool vertex = true>
    void path_query(int u, int v, auto f) const {
        while (leader(u) != leader(v)){
            if (down[u] < down[v]){
                f(down[leader(v)], down[v] + 1);
                v = ~nxt[leader(v)];
            }
            else {
                f(down[u] + 1, down[leader(u)]);
                u = ~nxt[leader(u)];
            }
        }
        if constexpr (vertex){
            if (down[u] < down[v]){
                f(down[u], down[v] + 1);
            }
            else {
                f(down[u] + 1, down[v]);
            }
        }
        else {
            if (down[u] != down[v]){
                f(down[u] + 1, down[v] + 1);
            }
        }
    }

    // {parent, mapping} : cptree i is correspond to tree mapping[i]. parent[i] is parent of i in cptree.
    // parent[i] < i, parent[0] == -1
	std::pair<std::vector<int>, std::vector<int>> compressed_tree(std::vector<int> vs) const {
        if (vs.empty()){
            return {{},{}};
        }
        auto comp = [&](int l, int r){
            return down[l] < down[r];
        };
		std::ranges::sort(vs, comp);
		int sz = vs.size(); vs.reserve(2*sz);
        for (int i = 0; i < sz-1; i++){
            vs.emplace_back(lca(vs[i], vs[i+1]));
        }
        std::sort(vs.begin() + sz, vs.end(), comp);
        std::ranges::inplace_merge(vs, vs.begin() + sz, comp);
        auto del = std::ranges::unique(vs);
        vs.erase(del.begin(), del.end());
        sz = vs.size();
        std::stack<int> st;
        std::vector<int> par(sz);
        par[0] = -1;
        st.push(0);
        for (int i = 1; i < sz; i++){
            while (!is_in_subtree(vs[st.top()], vs[i])) st.pop();
            par[i] = st.top();
            st.push(i);
        }
        return {par, vs};
	}

//*  CSR

	// build csr for using operator()
	void build_csr(){
		childs = noya2::internal::csr<int>(n, n - 1);
        for (int v = 0; v < n; v++){
            if (v == root) continue;
            if (leader(v) != v){
                childs.add(parent(v),v);
            }
        }
		for (int v = 0; v < n; v++){
			if (v == root) continue;
            if (leader(v) == v){
                childs.add(parent(v),v);
            }
		}
		childs.build();
	}
	const auto operator()(int v) const {
		return childs[v];
	}
	auto operator()(int v){
		return childs[v];
	}
//*/

    // hld_tree g;
    // euler tour order : `for (int v : g)`
    // with range_adaptor : `for (int v : g | std::views::reverse)`
    // bottom-up DP : `for (int v : g | std::views::drop(1) | std::views::reverse){ update dp[g.parent(v)] by dp[v] }`
    auto begin() const {
        return tour.begin();
    }
    auto end() const {
        return tour.end();
    }

  private:
    // nxt[v] : parent of v, nxt[0] == -1
    void build_from_parents(){
        for (int u = n - 1; u >= 1; u--){
            int v = nxt[u];
            sub[v] += sub[u];
            down[v] = std::max(down[v], sub[u]);
        }
        for (int u = n - 1; u >= 1; u--){
            int v = nxt[u];
            if (down[v] == sub[u]){
                sub[u] = ~sub[u];
                down[v] = ~down[v];
            }
        }

        sub[0] = ~down[0] + 1;
        down[0] = 0;
        for (int u = 1; u < n; u++){
            int v = nxt[u];
            int nsub = ~down[u] + 1;
            if (sub[u] < 0){
                down[u] = down[v] + 1;
                nxt[u] = (nxt[v] < 0 ? v : nxt[v]);
            }
            else {
                down[u] = down[v] + sub[v];
                sub[v] += sub[u];
                nxt[u] = ~v;
            }
            sub[u] = nsub;
        }

        for (int u = 0; u < n; u++){
            tour[down[u]] = u;
        }
    }

    // down[v] : degree of v
    // nxt[v] : xor prod of neighbor of v
    void build_from_edges(){
        // use tour as queue
        int back = 0;
        for (int u = 0; u < n; u++){
            if (u != root && down[u] == 1){
                tour[back++] = u;
            }
        }
        for (int front = 0; front < n - 1; front++){
            int u = tour[front];
            down[u] = -1;
            int v = nxt[u]; // parent of v
            nxt[v] ^= u;
            if (--down[v] == 1 && v != root){
                tour[back++] = v;
            }
        }
        // check : now, tour is reverse of topological order

        tour.pop_back();

        // check : now, down[*] <= 1
        for (int u : tour){
            int v = nxt[u];
            // subtree size (initialized (1,1,...,1))
            sub[v] += sub[u];
            // heaviest subtree of its child
            down[v] = std::max(down[v], sub[u]);
        }
        for (int u : tour){
            int v = nxt[u];
            // whether u is not the top of heavy path
            if (down[v] == sub[u]){
                sub[u] = ~sub[u];
                down[v] = ~down[v];
            }
        }

        // after appearing v as u (or v == root), 
        // down[v] is the visiting time of euler tour
        // nxt[v] is the lowest vertex of heavy path which contains v
        //   (if v itself, nxt[v] is ~(parent of v))
        // sub[v] + down[v] is the light child's starting time of euler tour
        // note : heavy child's visiting time of euler tour is (the time of its parent) + 1
        sub[root] = ~down[root] + 1;
        down[root] = 0;
        nxt[root] = -1;
        for (int u : tour | std::views::reverse){
            int v = nxt[u];
            int nsub = ~down[u] + 1;
            // heavy child
            if (sub[u] < 0){
                down[u] = down[v] + 1;
                nxt[u] = (nxt[v] < 0 ? v : nxt[v]);
            }
            // light child
            else {
                down[u] = down[v] + sub[v];
                sub[v] += sub[u];
                nxt[u] = ~v;
            }
            sub[u] = nsub;
        }

        // tour is inverse permutation of down
        tour.push_back(0);
        for (int u = 0; u < n; u++){
            tour[down[u]] = u;
        }
    }
};

} // namespace noya2

namespace noya2 {

struct grid {
    int h, w;
    grid (int _h = 0, int _w = 0) : h(_h), w(_w) {}
    int idx(int x, int y) const {
        return x * w + y;
    }
    std::pair<int,int> pos(int id) const {
        return {id / w, id % w};
    }
    bool operator()(int x, int y) const {
        return 0 <= x && x < h && 0 <= y && y < w;
    }
    bool operator()(int id) const {
        return operator()(id / w, id % w);
    }
    static constexpr std::array<std::pair<int,int>, 4> dxys = {std::pair<int,int>{0, 1}, {-1, 0}, {0, -1}, {1, 0}};
    auto adj4(int x, int y) const {
        return dxys | std::views::transform([x, y](std::pair<int,int> dxy){
            return std::pair<int,int>(dxy.first + x, dxy.second + y);
        }) | std::views::filter([this](std::pair<int,int> xy){
            return operator()(xy.first, xy.second);
        });
    }
    auto adj4(int id) const {
        return adj4(id / w, id % w) | std::ranges::views::transform([this](std::pair<int,int> xy){
            return idx(xy.first, xy.second);
        });
    }
};

} // namespace noya2

namespace nachia{

struct CInStream{
private:
	static const unsigned int INPUT_BUF_SIZE = 1 << 17;
	unsigned int p = INPUT_BUF_SIZE;
	static char Q[INPUT_BUF_SIZE];
public:
	using MyType = CInStream;
	char seekChar(){
		if(p == INPUT_BUF_SIZE){
			size_t len = fread(Q, 1, INPUT_BUF_SIZE, stdin);
			if(len != INPUT_BUF_SIZE) Q[len] = '\0';
			p = 0;
		}
		return Q[p];
	}
	void skipSpace(){ while(isspace(seekChar())) p++; }
private:
	template<class T, int sp = 1>
	T nextUInt(){
		if constexpr (sp) skipSpace();
		T buf = 0;
		while(true){
			char tmp = seekChar();
			if('9' < tmp || tmp < '0') break;
			buf = buf * 10 + (tmp - '0');
			p++;
		}
		return buf;
	}
public:
	uint32_t nextU32(){ return nextUInt<uint32_t>(); }
	int32_t nextI32(){
		skipSpace();
		if(seekChar() == '-'){
			p++; return (int32_t)(-nextUInt<uint32_t, 0>());
		}
		return (int32_t)nextUInt<uint32_t, 0>();
	}
	uint64_t nextU64(){ return nextUInt<uint64_t>();}
	int64_t nextI64(){
		skipSpace();
		if(seekChar() == '-'){
			p++; return (int64_t)(-nextUInt<int64_t, 0>());
		}
		return (int64_t)nextUInt<int64_t, 0>();
	}
	template<class T>
	T nextInt(){
		skipSpace();
		if(seekChar() == '-'){
			p++;
			return - nextUInt<T, 0>();
		}
		return nextUInt<T, 0>();
	}
	char nextChar(){ skipSpace(); char buf = seekChar(); p++; return buf; }
	std::string nextToken(){
		skipSpace();
		std::string buf;
		while(true){
			char ch = seekChar();
			if(isspace(ch) || ch == '\0') break;
			buf.push_back(ch);
			p++;
		}
		return buf;
	}
	MyType& operator>>(unsigned int& dest){ dest = nextU32(); return *this; }
	MyType& operator>>(int& dest){ dest = nextI32(); return *this; }
	MyType& operator>>(unsigned long& dest){ dest = nextU64(); return *this; }
	MyType& operator>>(long& dest){ dest = nextI64(); return *this; }
	MyType& operator>>(unsigned long long& dest){ dest = nextU64(); return *this; }
	MyType& operator>>(long long& dest){ dest = nextI64(); return *this; }
	MyType& operator>>(std::string& dest){ dest = nextToken(); return *this; }
	MyType& operator>>(char& dest){ dest = nextChar(); return *this; }
} cin;

struct FastOutputTable{
	char LZ[1000][4] = {};
	char NLZ[1000][4] = {};
	constexpr FastOutputTable(){
		using u32 = uint_fast32_t;
		for(u32 d=0; d<1000; d++){
			LZ[d][0] = ('0' + d / 100 % 10);
			LZ[d][1] = ('0' + d /  10 % 10);
			LZ[d][2] = ('0' + d /   1 % 10);
			LZ[d][3] = '\0';
		}
		for(u32 d=0; d<1000; d++){
			u32 i = 0;
			if(d >= 100) NLZ[d][i++] = ('0' + d / 100 % 10);
			if(d >=  10) NLZ[d][i++] = ('0' + d /  10 % 10);
			if(d >=   1) NLZ[d][i++] = ('0' + d /   1 % 10);
			NLZ[d][i++] = '\0';
		}
	}
};

struct COutStream{
private:
	using u32 = uint32_t;
	using u64 = uint64_t;
	using MyType = COutStream;
	static const u32 OUTPUT_BUF_SIZE = 1 << 17;
	static char Q[OUTPUT_BUF_SIZE];
	static constexpr FastOutputTable TB = FastOutputTable();
	u32 p = 0;
	static constexpr u32 P10(u32 d){ return d ? P10(d-1)*10 : 1; }
	static constexpr u64 P10L(u32 d){ return d ? P10L(d-1)*10 : 1; }
	template<class T, class U> static void Fil(T& m, U& l, U x){ m = l/x; l -= m*x; }
public:
	void next_dig9(u32 x){
		u32 y;
		Fil(y, x, P10(6));
		nextCstr(TB.LZ[y]);
		Fil(y, x, P10(3));
		nextCstr(TB.LZ[y]); nextCstr(TB.LZ[x]);
	}
	void nextChar(char c){
		Q[p++] = c;
		if(p == OUTPUT_BUF_SIZE){ fwrite(Q, p, 1, stdout); p = 0; }
	}
	void nextEoln(){ nextChar('\n'); }
	void nextCstr(const char* s){ while(*s) nextChar(*(s++)); }
	void nextU32(uint32_t x){
		u32 y = 0;
		if(x >= P10(9)){
			Fil(y, x, P10(9));
			nextCstr(TB.NLZ[y]); next_dig9(x);
		}
		else if(x >= P10(6)){
			Fil(y, x, P10(6));
			nextCstr(TB.NLZ[y]);
			Fil(y, x, P10(3));
			nextCstr(TB.LZ[y]); nextCstr(TB.LZ[x]);
		}
		else if(x >= P10(3)){
			Fil(y, x, P10(3));
			nextCstr(TB.NLZ[y]); nextCstr(TB.LZ[x]);
		}
		else if(x >= 1) nextCstr(TB.NLZ[x]);
		else nextChar('0');
	}
	void nextI32(int32_t x){
		if(x >= 0) nextU32(x);
		else{ nextChar('-'); nextU32((u32)-x); }
	}
	void nextU64(uint64_t x){
		u32 y = 0;
		if(x >= P10L(18)){
			Fil(y, x, P10L(18));
			nextU32(y);
			Fil(y, x, P10L(9));
			next_dig9(y); next_dig9(x);
		}
		else if(x >= P10L(9)){
			Fil(y, x, P10L(9));
			nextU32(y); next_dig9(x);
		}
		else nextU32(x);
	}
	void nextI64(int64_t x){
		if(x >= 0) nextU64(x);
		else{ nextChar('-'); nextU64((u64)-x); }
	}
	template<class T>
	void nextInt(T x){
		if(x < 0){ nextChar('-'); x = -x; }
		if(!(0 < x)){ nextChar('0'); return; }
		std::string buf;
		while(0 < x){
			buf.push_back('0' + (int)(x % 10));
			x /= 10;
		}
		for(int i=(int)buf.size()-1; i>=0; i--){
			nextChar(buf[i]);
		}
	}
	void writeToFile(bool flush = false){
		fwrite(Q, p, 1, stdout);
		if(flush) fflush(stdout);
		p = 0;
	}
	COutStream(){ Q[0] = 0; }
	~COutStream(){ writeToFile(); }
	MyType& operator<<(unsigned int tg){ nextU32(tg); return *this; }
	MyType& operator<<(unsigned long tg){ nextU64(tg); return *this; }
	MyType& operator<<(unsigned long long tg){ nextU64(tg); return *this; }
	MyType& operator<<(int tg){ nextI32(tg); return *this; }
	MyType& operator<<(long tg){ nextI64(tg); return *this; }
	MyType& operator<<(long long tg){ nextI64(tg); return *this; }
	MyType& operator<<(const std::string& tg){ nextCstr(tg.c_str()); return *this; }
	MyType& operator<<(const char* tg){ nextCstr(tg); return *this; }
	MyType& operator<<(char tg){ nextChar(tg); return *this; }
} cout;

char CInStream::Q[INPUT_BUF_SIZE];
char COutStream::Q[OUTPUT_BUF_SIZE];

} // namespace nachia

nachia::CInStream ncin;
nachia::COutStream ncout;

int main(){
    int h, w; ncin >> h >> w;
    grid g(h,w);
    int hw = h*w;
    vector<int> a(hw);
    rep(i,hw) ncin >> a[i];
    vector<int> vs(hw); iota(all(vs),0);
    sort(all(vs),[&](int l, int r){
        return a[l] < a[r];
    });
    vector<int> top(hw*2); iota(all(top),0);
    auto _leader = [&](auto self, int v){
        if (top[v] == v) return v;
        return top[v] = self(self,top[v]);
    };
    auto leader = [&](int v){
        return _leader(_leader,v);
    };
    vector<int> par(hw*2-1);
    int id = hw-2;
    vector<int> cs(hw);
    auto merge = [&](int u, int v, int c){
        u += hw-1;
        v += hw-1;
        u = leader(u);
        v = leader(v);
        if (u == v) return ;
        top[u] = id;
        top[v] = id;
        par[u] = id;
        par[v] = id;
        cs[id] = c;
        id--;
    };
    for (auto ij : vs){
        auto [i, j] = g.pos(ij);
        for (auto [x, y] : g.adj4(i,j)){
            int xy = g.idx(x,y);
            if (a[xy] > a[ij]) continue;
            if (a[xy] == a[ij] && xy > ij) continue;
            merge(ij,xy,a[ij]);
        }
    }
    hld_tree tr(std::move(par));
    int q; ncin >> q;
    while (q--){
        int sx, sy, gx, gy; ncin >> sx >> sy >> gx >> gy; sx--, sy--, gx--, gy--;
        ncout << cs[tr.lca(g.idx(sx,sy) + hw-1, g.idx(gx,gy) + hw-1)] << '\n';
    }
}