#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
template<class T> using V = vector<T>;
using VI = V<int>;
using VL = V<ll>;
using VS = V<string>;
template<class T> using PQ = priority_queue<T, V<T>, greater<T>>;
using graph = V<VI>;
template<class T> using w_graph = V<V<pair<int, T>>>;
#define FOR(i,a,n) for(int i=(a);i<(n);++i)
#define eFOR(i,a,n) for(int i=(a);i<=(n);++i)
#define rFOR(i,a,n) for(int i=(n)-1;i>=(a);--i)
#define erFOR(i,a,n) for(int i=(n);i>=(a);--i)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define out(y,x) ((y)<0||h<=(y)||(x)<0||w<=(x))
#ifdef _DEBUG
#define line cout << "-----------------------------\n"
#define stop system("pause")
#endif
constexpr ll INF = 1000000000;
constexpr ll LLINF = 1LL << 60;
constexpr ll mod = 1000000007;
constexpr ll MOD = 998244353;
constexpr ld eps = 1e-10;
template<class T>inline bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; }return false; }
template<class T>inline bool chmin(T& a, const T& b) { if (a > b) { a = b; return true; }return false; }
inline void init() { cin.tie(nullptr); cout.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); }
template<class T>inline istream& operator>>(istream& is, V<T>& v) { for (auto& a : v)is >> a; return is; }
template<class T, class U>inline istream& operator>>(istream& is, pair<T, U>& p) { is >> p.first >> p.second; return is; }
template<class T>inline V<T> vec(size_t a) { return V<T>(a); }
template<class T>inline V<T> defvec(T def, size_t a) { return V<T>(a, def); }
template<class T, class... Ts>inline auto vec(size_t a, Ts... ts) { return V<decltype(vec<T>(ts...))>(a, vec<T>(ts...)); }
template<class T, class... Ts>inline auto defvec(T def, size_t a, Ts... ts) { return V<decltype(defvec<T>(def, ts...))>(a, defvec<T>(def, ts...)); }
template<class T>inline void print(const T& a) { cout << a << "\n"; }
template<class T, class... Ts>inline void print(const T& a, const Ts&... ts) { cout << a << " "; print(ts...); }
template<class T>inline void print(const V<T>& v) { for (int i = 0; i < v.size(); ++i)cout << v[i] << (i == v.size() - 1 ? "\n" : " "); }
template<class T>inline void print(const V<V<T>>& v) { for (auto& a : v)print(a); }
template<class T>inline T sum(const V<T>& a, int l, int r) { return a[r] - (l == 0 ? 0 : a[l - 1]); }
template<class T>inline void END(T s) { print(s); exit(0); }
void END() { exit(0); }

class unionfind {
    VI par, rank;
    int forest_num;
public:
    unionfind(){}
    unionfind(const int& n) : par(n), rank(n, 1), forest_num(n) {
        FOR(i, 0, n)par[i] = i;
    }
    int root(int x) {
        if (par[x] == x)return x;
        return par[x] = root(par[x]);
    }
    int size(int x) {
        if (par[x] == x)return rank[x];
        return size(par[x]);
    }
    void unite(int x, int y) {
        int rx = root(x), ry = root(y);
        if (rx == ry)return;
        if (rank[rx] < rank[ry]) {
            par[rx] = ry;
            rank[ry] += rank[rx];
        }
        else {
            par[ry] = rx;
            rank[rx] += rank[ry];
        }
        --forest_num;
    }
    bool same(int x, int y) { return root(x) == root(y); }
    int fnum() { return forest_num; }
};

class manager {
public:
    int n, m, cnt = 3000;
    VS s;
    manager(int n, int m) :n(n), m(m) {
        s = VS(n, string(n, '?'));
    }
    char query(int y, int x) {
        if (s[y][x] == '?') {
            if (max(y, x) == 0 || min(y, x) == n - 1) {
                s[y][x] == 'B';
                --m;
            }
            else {
                if (cnt == 0)return 'X';
                cout << y + 1 << " " << x + 1 << endl;
                string t; cin >> t;
                if (t == "-1")return 'X';
                s[y][x] = t[0];
                m -= s[y][x] == 'B';
                --cnt;
            }
        }
        return s[y][x];
    }
    bool end() {
        return m == 0;
    }
};

int main() {
    init();

    int n, m; cin >> n >> m;
    unionfind uf(n * n);
#define g(y,x) ((y)*w+x)
    int h = n, w = n;
    manager ma(n, m);
    ma.query(0, 0);
    auto dp = defvec<int>(INF, n, n);
    dp[0][0] = 0;
    int dy[] = { -1,0,1,0 }, dx[] = { 0,1,0,-1 };
    auto dfs = [&](auto&& f, int y, int x)->bool {
        if (y == n - 1 && x == n - 1)return true;
        if (ma.end())return false;
        bool res = false;
        FOR(i, 0, 4) {
            int ny = y + dy[i], nx = x + dx[i];
            if (out(ny, nx))continue;
            if (char c = ma.query(ny, nx); c == 'W')continue;
            else if (c == 'X')return false;
            if (chmin(dp[ny][nx], dp[y][x] + 1))res |= f(f, ny, nx);
        }
        return res;
    };
    print(dfs(dfs, 0, 0) ? "Yes" : "No");

    return 0;
}