#pragma GCC target("avx2")
#pragma GCC optimize("03")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std; typedef long double ld; typedef long long ll;
typedef unsigned long long ull;
#define endl "\n"
#define FOR(i,a,b) for(int i=(a);i<=(b);i++)
#define rep(i,n) for(int i=0;i<(n);i++)
#define PII pair<int, int>
#define PLL pair<ll, ll>
#define ALL(x) (x).begin(), (x).end()
int dx[] = {1, 0, -1, 0}; int dy[] = {0, 1, 0, -1};
constexpr int INF=1<<30;
constexpr ll LINF=1LL<<60; 
constexpr ll mod=1e9+7;
template<class T>vector<T> vec(int len, T elem) { return vector<T>(len, elem); } // auto dp = vec(52, vec(103, vec(103, INF)));
template<class T>inline bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T>inline bool chmin(T &a, const T &b) { if (b<a) { a = b; return 1; } return 0; }
template<class T>inline int popcount(T a) {return __builtin_popcount(a);}
template<class T>inline T emod(T a, T p) { return (a%p + p) % p;}
template <typename T> istream &operator>>(istream &is, vector<T> &vec) { for (auto &v : vec) is >> v; return is; }
template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) {os << '\n'; for (auto v : vec) os << v << ' '; os << '\n'; return os;}
template <typename T> ostream &operator<<(ostream &os, const deque<T> &vec) { os << "deq["; for (auto v : vec) os << v << ','; os << ']'; return os; }
template <typename T> ostream &operator<<(ostream &os, const set<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T> ostream &operator<<(ostream &os, const unordered_set<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T> ostream &operator<<(ostream &os, const unordered_multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &pa) { os << '(' << pa.first << ',' << pa.second << ')'; return os; }
template <typename TK, typename TV> ostream &operator<<(ostream &os, const map<TK, TV> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }
template <typename TK, typename TV> ostream &operator<<(ostream &os, const unordered_map<TK, TV> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }
struct MyIO {
    MyIO(){
        cin.tie(0); 
        ios::sync_with_stdio(false); 
        cout << fixed << setprecision(15);
    }
} IO_OI;
#ifdef LOCAL
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << " " << H;
    debug_out(T...);
}
#define debug(...) \
    cerr << __LINE__ << " [" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define dump(x) cerr << __LINE__ << " " << #x << " = " << (x) << endl
#else
#define debug(...) (void(0))
#define dump(x) (void(0))
#endif
//-------------------
struct GridUnionFind
{
    int H, W;
    std::vector<int> par, cou;
    using P = std::pair<int, int>;
    GridUnionFind(int H_, int W_) : H(H_), W(W_), par(H * W), cou(H * W, 1) { std::iota(par.begin(), par.end(), 0); }
    inline int id_(int h, int w) { return h * W + w; }
    inline bool coordinate_valid(int h, int w) { return h >= 0 and h < H and w >= 0 and w < W; }
    int _find(int x) { return (par[x] == x) ? x : (par[x] = _find(par[x])); }
    bool _unite(int x, int y) {
        x = _find(x), y = _find(y); if (x == y) return false;
        if (cou[x] < cou[y]) std::swap(x, y);
        par[y] = x, cou[x] += cou[y];
        return true;
    }
    int find(int h, int w) {
        assert(coordinate_valid(h, w));
        return _find(id_(h, w));
    }
    bool unite(int h, int w, int h2, int w2) {
        assert(coordinate_valid(h, w) and coordinate_valid(h2, w2));
        return _unite(id_(h, w), id_(h2, w2));
    }
    int count(int h, int w) { return cou[find(h, w)]; }
    bool same(int h, int w, int h2, int w2) { return find(h, w) == find(h2, w2); }
};

int main() {
    int H,W;cin>>H>>W;
    GridUnionFind uf(H, W);
    auto on = [&](int h, int w) {
        if(h<0 or h>=H) return false;
        if(w<0 or w>=W) return false;
        return true;
    };
    auto a = vec(H, vec(W, 0));
    rep(i,H)rep(j,W) {
        cin >> a[i][j];
    }
    rep(i,H)rep(j,W) {
        rep(k, 4) {
            int ni = i+dy[k];
            int nj = j+dx[k];
            if(on(ni, nj) and a[ni][nj]==a[i][j]) uf.unite(ni,nj,i,j);
        }
    }

    unordered_map<int,int>mp;
    rep(i,H)rep(j,W) {
        if(a[i][j]==1) mp[uf.find(i,j)]++;
    }
    cout << mp.size() << endl;
}