func_code_string: #include <bits/stdc++.h>   using namespace std;   int mm[110][110];   int tmp[110][110];   void draw(int a, int b, int v) {     for (int lx = 0; lx < a; lx++)       for (int ly = 0; ly < b; ly++) tmp[lx][ly] += v;     return;   }   void prt(int a, int b) {     for (int lx = 0; lx < a; lx++) {       for (int ly = 0; ly < b; ly++) printf( %c , tmp[lx][ly] ?  W  :  B );       puts(  );     }     return;   }   int main() {     int n, m;     scanf( %d %d , &n, &m);     for (int lx = 0; lx < n; lx++) {       char buf[200];       scanf( %s , buf);       for (int ly = 0; ly < m; ly++) mm[lx][ly] = (buf[ly] ==  W );     }     int cnt = 1;     for (int lx = 0; lx < n; lx++)       for (int ly = 0; ly < m; ly++) tmp[lx][ly] = mm[n - 1][m - 1];     for (int cc = n + m - 3; cc >= 0; cc--) {       for (int x = 0; x <= cc; x++) {         int y = cc - x;         if (x >= n or y >= m) continue;         if (tmp[x][y] != mm[x][y]) {           draw(x + 1, y + 1, mm[x][y] - tmp[x][y]), cnt++;         }       }     }     printf( %d n , cnt);     return 0;   }   