func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxx = 600010;   const double pi = acos(-1.0);   const double eps = 1e-15;   stack<int> h;   vector<int> g[maxx];   int t, n, m;   int ans = 0, total = 0, sum = 0, cnt = 0;   int a[maxx], bj[maxx], vis[maxx], dfn[maxx], low[maxx];   char ch[3111];   char c[3111][3111], s[3111][3111];   void tarjan(int x, int father) {     dfn[x] = low[x] = ++cnt, vis[x] = 1, h.push(x);     for (int i = 0; i < g[x].size(); i++) {       int to = g[x][i];       if (to == father) continue;       if (!dfn[to]) {         tarjan(to, x);         low[x] = min(low[x], low[to]);       } else if (vis[to])         low[x] = min(low[x], dfn[to]);     }     if (low[x] == dfn[x]) {       bj[x] = ++total, vis[x] = 0;       while (h.top() != x) {         bj[h.top()] = total, vis[h.top()] = 0, h.pop();       }       h.pop();     }   }   int main() {     scanf( %d , &n);     for (int i = 1; i <= n; i++)       for (int j = 1; j <= n; j++) scanf(  %c , &c[i][j]);     for (int i = 1; i <= n; i++)       for (int j = 1; j <= n; j++) scanf(  %c , &s[i][j]);     for (int i = 1; i <= n; i++) scanf(  %c , &ch[i]);     for (int i = 1; i <= n; i++)       for (int j = 1; j <= n; j++) {         if (c[i][j] ==  0 ) {           if (s[i][j] ==  1 ) {             if (ch[j] ==  0  && ch[i] ==  0 ) {               ans = -1;               i = n + 1;               break;             }             if (ch[j] ==  0  && ch[i] ==  1 ) g[j + 3 * n].push_back(j + n);             if (ch[j] ==  1  && ch[i] ==  0 ) g[i + 2 * n].push_back(i);             if (ch[j] ==  1  && ch[i] ==  1 )               g[i].push_back(j + 3 * n), g[j + 3 * n].push_back(i),                   g[i + 2 * n].push_back(j + n), g[j + n].push_back(i + 2 * n);           } else {             if (ch[j] ==  0  && ch[i] ==  1 ) g[j + n].push_back(j + 3 * n);             if (ch[j] ==  1  && ch[i] ==  0 ) g[i].push_back(i + 2 * n);             if (ch[j] ==  1  && ch[i] ==  1 )               g[i].push_back(j + n), g[j + n].push_back(i),                   g[i + 2 * n].push_back(j + 3 * n),                   g[j + 3 * n].push_back(i + 2 * n);           }         } else {           if (s[i][j] ==  1 ) {             if (ch[j] ==  0  && ch[i] ==  1 ) g[j + n].push_back(j + 3 * n);             if (ch[j] ==  1  && ch[i] ==  0 ) g[i].push_back(i + 2 * n);             if (ch[j] ==  1  && ch[i] ==  1 )               g[i].push_back(j + n), g[i + 2 * n].push_back(j + 3 * n),                   g[j + n].push_back(i), g[j + 3 * n].push_back(i + 2 * n);           } else {             if (ch[j] ==  0  && ch[i] ==  0 ) {               i = n + 1;               ans = -1;               break;             }             if (ch[j] ==  0  && ch[i] ==  1 ) g[j + 3 * n].push_back(j + n);             if (ch[j] ==  1  && ch[i] ==  0 ) g[i + 2 * n].push_back(i);             if (ch[j] ==  1  && ch[i] ==  1 )               g[j + n].push_back(i + 2 * n), g[i].push_back(j + 3 * n),                   g[i + 2 * n].push_back(j + n), g[j + 3 * n].push_back(i);           }         }       }     if (ans)       printf( %d , ans);     else {       for (int i = 1; i <= 4 * n; i++)         if (!dfn[i]) tarjan(i, i);       for (int i = 1; i <= 2 * n; i++)         if (bj[i] == bj[i + 2 * n]) {           ans = 1;           break;         }       if (ans)         printf( -1 );       else {         for (int i = 1; i <= n; i++)           if (bj[i] < bj[i + 2 * n]) ans++;         for (int i = n + 1; i <= 2 * n; i++)           if (bj[i] < bj[i + 2 * n]) ans++;         printf( %d n , ans);         for (int i = 1; i <= n; i++)           if (bj[i] < bj[i + 2 * n]) printf( row %d n , i - 1);         for (int i = n + 1; i <= 2 * n; i++)           if (bj[i] < bj[i + 2 * n]) printf( col %d n , i - n - 1);       }     }     return 0;   }   