#include using namespace std; typedef signed long long ll; #define _P(...) (void)printf(__VA_ARGS__) #define FOR(x,to) for(x=0;x<(to);x++) #define FORR(x,arr) for(auto& x:arr) #define FORR2(x,y,arr) for(auto& [x,y]:arr) #define ALL(a) (a.begin()),(a.end()) #define ZERO(a) memset(a,0,sizeof(a)) #define MINUS(a) memset(a,0xff,sizeof(a)) template bool chmax(T &a, const T &b) { if(a bool chmin(T &a, const T &b) { if(a>b){a=b;return 1;}return 0;} //------------------------------------------------------- int H,W; string A[1010]; template class UF { public: vector par,rank,cnt,G[um]; UF() {par=rank=vector(um,0); cnt=vector(um,1); for(int i=0;irank[y]) return par[x]=y; rank[x]+=rank[x]==rank[y]; return par[y]=x; } }; UF<1010101> uf; void solve() { int i,j,k,l,r,x,y; string s; cin>>H>>W; FOR(y,H) { cin>>A[y]; FOR(x,W) { if(y&&A[y][x]==A[y-1][x]) uf(y*W+x,(y-1)*W+x); if(x&&A[y][x]==A[y][x-1]) uf(y*W+x,(y+0)*W+x-1); } } FOR(y,H) { FOR(x,W) if(uf.count(y*H+x)>=4) A[y][x]='.'; cout<