#include <iostream> #include <string> using namespace std; int par[200010],sz[200010]; void init(int n){ for(int i=0;i<n;i++) par[i] = i,sz[i] = 1; } int find(int x){ if(par[x]==x) return x; return par[x] = find(par[x]); } void unite(int x, int y){ x = find(x); y = find(y); if(x==y) return; if(sz[x]>sz[y]) swap(x,y); par[x] = y; sz[y] += sz[x]; } bool same(int x, int y){ return find(x)==find(y); } int query(int a,int b){ cout << a + 1 << " " << b + 1 << endl; string t; cin >> t; if(t[0]=='B') return 1; else return 0; } bool used[1010][1010]; int mp[1010][1010]; void dfs(int x,int y,int n){ if(used[x][y]) return; used[x][y] = true; int z = query(x,y); mp[x][y] = z; if(!mp[x][y]) return; if(x + 1<n) dfs(x + 1,y,n); if(x - 1>=0) dfs(x - 1,y,n); if(y + 1<n) dfs(x,y + 1,n); if(y - 1>=0) dfs(x,y - 1,n); } int main(){ int i,j,n,m; cin >> n >> m; for(i=0;i<n;i++){ for(j=0;j<n;j++) used[i][j] = false; } dfs(0,0,n); if(used[n - 1][n - 1]) cout << "Yes" << endl; else cout << "No" << endl; }