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

int a[502][502];

int main() {
    int n, m;
    cin >> n >> m;

    for (int i = 0; i <= n + 1; i++) {
        for (int j = 0; j <= n + 1; j++) {
            a[i][j] = -1;
        }
    }
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            a[i][j] = 0;
        }
    }

    a[1][1] = 1;
    a[n][n] = 1;

    queue<pair<int, int>> q;
    q.push({ 1, 1 });

    while (!q.empty()) {
        auto p = q.front(); q.pop();
        pair<int, int> d[4] = { { 0, 1 }, { 0, -1 }, { 1, 0 }, { -1, 0 } };
        for (int k = 0; k < 4; k++) {
            auto t = p;
            t.first += d[k].first;
            t.second += d[k].second;
            if (t.first == n && t.second == n) {
                cout << "Yes" << endl;
                exit(0);
            }
            int x = a[t.first][t.second];
            if (x != 0) continue;
            cout << t.first << ' ' << t.second << endl;
            string s;
            cin >> s;
            a[t.first][t.second] = s[0] == 'B' ? 1 : 2;
            if (a[t.first][t.second] == 1) {
                q.push(t);
            }
        }
    }
    cout << "No" << endl;

    return 0;
}