#include #pragma GCC optimize("Ofast") #define _GLIBCXX_DEBUG using namespace std; using std::cout; using std::cin; using std::endl; using ll=long long; using ld=long double; ll I=1167167167167167167; ll Q=1e9+7; #define rep(i,a) for (ll i=0;i using _pq = priority_queue, greater>; template ll LB(vector &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();} template ll UB(vector &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();} template bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;} template bool chmax(T &a,const T &b){if(a void So(vector &v) {sort(v.begin(),v.end());} template void Sore(vector &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});} template void print_tate(vector &v) {rep(i,v.size()) cout<>N>>M; vector> p(N+2,vector(N+2)); p[1][1]=1; p[N][N]=-2; queue> q; q.push({1,1}); int J=1; int dx[]={1,-1,0,0}; int dy[]={0,0,1,-1}; rep(i,N+2) p[0][i]=-1,p[i][0]=-1,p[i][N+1]=-1,p[N+1][i]=-1; while(!q.empty()&&J){ int a,b; tie(a,b)=q.front(); q.pop(); rep(i,4){ int s=a+dx[i],t=b+dy[i]; if(p[s][t]==-2){ J=0; break; } if(p[s][t]==0){ cout<>S; if(S[0]=='B'){ p[s][t]=1; q.push({s,t}); } else p[s][t]=-1; } } } yneos(!J); return 0; }