#pragma GCC optimize ("Ofast") #include using namespace std; inline void rd(int &x){ int k; int m=0; x=0; for(;;){ k = getchar_unlocked(); if(k=='-'){ m=1; break; } if('0'<=k&&k<='9'){ x=k-'0'; break; } } for(;;){ k = getchar_unlocked(); if(k<'0'||k>'9'){ break; } x=x*10+k-'0'; } if(m){ x=-x; } } inline void rd(char &c){ int i; for(;;){ i = getchar_unlocked(); if(i!=' '&&i!='\n'&&i!='\r'&&i!='\t'&&i!=EOF){ break; } } c = i; } inline int rd(char c[]){ int i; int sz = 0; for(;;){ i = getchar_unlocked(); if(i!=' '&&i!='\n'&&i!='\r'&&i!='\t'&&i!=EOF){ break; } } c[sz++] = i; for(;;){ i = getchar_unlocked(); if(i==' '||i=='\n'||i=='\r'||i=='\t'||i==EOF){ break; } c[sz++] = i; } c[sz]='\0'; return sz; } inline void wt_L(char a){ putchar_unlocked(a); } inline void wt_L(int x){ int s=0; int m=0; char f[10]; if(x<0){ m=1; x=-x; } while(x){ f[s++]=x%10; x/=10; } if(!s){ f[s++]=0; } if(m){ putchar_unlocked('-'); } while(s--){ putchar_unlocked(f[s]+'0'); } } int X; int Y; char A[2000][2002]; priority_queue>> q; set> alr; int main(){ int sx; int sy; int nx; int ny; int dist; int ndist; int cost; int ncost; int d; int dx[4] = {-1,1,0,0}; int dy[4] = {0,0,-1,1}; rd(X); rd(Y); { int Lj4PdHRW; for(Lj4PdHRW=(0);Lj4PdHRW<(X);Lj4PdHRW++){ rd(A[Lj4PdHRW]); } } q.push(make_pair(-1,make_pair((X-1)*Y+Y-1,1))); for(;;){ dist = q.top().first; sx = q.top().second.first / Y; sy = q.top().second.first % Y; cost = q.top().second.second; if(sx==0 && sy==0){ wt_L(-dist-cost); wt_L('\n'); return 0; } q.pop(); if(alr.count(make_pair(sx*Y+sy, cost))){ continue; } alr.insert(make_pair(sx*Y+sy, cost)); for(d=(0);d<(4);d++){ nx = sx + dx[d]; ny = sy + dy[d]; if(nx < 0 || ny < 0 || nx >= X || ny >= Y){ continue; } if(A[nx][ny]=='k'){ ncost = cost +1; } else{ ncost = cost +0; } ndist = dist - ncost; q.push(make_pair(ndist,make_pair(nx*Y+ny,ncost))); } } return 0; } // cLay varsion 20200112-1 // --- original code --- // int X, Y; // char A[2000][2002]; // // priority_queue>> q; // set> alr; // // { // int sx, sy, nx, ny, dist, ndist, cost, ncost, d; // int dx[4] = {-1,1,0,0}; // int dy[4] = {0,0,-1,1}; // rd(X,Y,A(X)); // q.push(make_pair(-1,make_pair((X-1)*Y+Y-1,1))); // for(;;){ // dist = q.top().first; // sx = q.top().second.first / Y; // sy = q.top().second.first % Y; // cost = q.top().second.second; // if(sx==0 && sy==0) wt(-dist-cost), return 0; // q.pop(); // if(alr.count(make_pair(sx*Y+sy, cost))) continue; // alr.insert(make_pair(sx*Y+sy, cost)); // rep(d,4){ // nx = sx + dx[d]; // ny = sy + dy[d]; // if(nx < 0 || ny < 0 || nx >= X || ny >= Y) continue; // ncost = cost + if[A[nx][ny]=='k', 1, 0]; // ndist = dist - ncost; // q.push(make_pair(ndist,make_pair(nx*Y+ny,ncost))); // } // } // }