func_code_string: #include <bits/stdc++.h>   using namespace std;   const int SOURCE = 0, SINK = 1;   struct edge {     int to, idx, cap;   };   vector<vector<edge>> adj;   vector<int> lvl, ptr;   int totalflow;   int dfs(int n, int f) {     if (n == SINK) {       totalflow += f;       return f;     }     if (lvl[n] == lvl[SINK]) return 0;     while (ptr[n] < (int)adj[n].size()) {       edge& e = adj[n][ptr[n]];       ptr[n]++;       if (lvl[e.to] == lvl[n] + 1 && e.cap > 0) {         int nf = dfs(e.to, min(f, e.cap));         if (nf) {           e.cap -= nf;           adj[e.to][e.idx].cap += nf;           return nf;         }       }     }     return 0;   }   bool runMaxFlow() {     lvl.assign(adj.size(), -1);     ptr.assign(adj.size(), 0);     lvl[SOURCE] = 0;     queue<int> bfs;     bfs.push(SOURCE);     while (!bfs.empty()) {       int t = bfs.front();       bfs.pop();       for (edge& e : adj[t]) {         if (lvl[e.to] != -1 || e.cap <= 0) continue;         lvl[e.to] = lvl[t] + 1;         bfs.push(e.to);       }     }     if (lvl[SINK] == -1) return false;     while (dfs(SOURCE, 1 << 30)) {     }     return true;   }   void initMaxFlow(int nodes) {     totalflow = 0;     adj.clear();     adj.resize(nodes);   }   void addEdge(int a, int b, int w) {     adj[a].push_back(edge{b, (int)adj[b].size(), w});     adj[b].push_back(edge{a, (int)adj[a].size() - 1, 0});   }   const int dr[] = {0, 0, -1, 1}, dc[] = {-1, 1, 0, 0};   int R, C, M, F, S, fw[22][22][22][22];   char gd[23][23];   struct scayger {     int r, c, t, g;   } sg[22 * 22 * 2 + 1];   bool try1(long long t, bool sgm) {     initMaxFlow(M + F + R * C * 2 + 3);     for (int r = 0; r < int(R); r++)       for (int c = 0; c < int(C); c++)         addEdge(M + F + 3 + (r * C + c) * 2, M + F + 3 + (r * C + c) * 2 + 1, 1);     for (int i = 0; i < int(M); i++) addEdge(0, 3 + i, 1);     for (int i = 0; i < int(F); i++) addEdge(M + 3 + i, 1, 1);     if (sgm)       addEdge(0, 2, 1);     else       addEdge(2, 1, 1);     for (int i = 0; i < int(S); i++) {       scayger& s = sg[i];       int g = s.g;       if (g == 0) g = (sgm) ? 1 : 2;       for (int r = 0; r < int(R); r++)         for (int c = 0; c < int(C); c++) {           long long d = fw[r][c][s.r][s.c];           if (d == -1) continue;           if (t >= d * s.t) {             if (g == 1)               addEdge(2 + i, M + F + 3 + (r * C + c) * 2, 1);             else               addEdge(M + F + 3 + (r * C + c) * 2 + 1, 2 + i, 1);           }         }     }     while (runMaxFlow()) {     }     return totalflow == S / 2;   }   bool tryit(long long t) { return try1(t, true) || try1(t, false); }   int main() {     scanf( %d%d%d%d , &R, &C, &M, &F);     for (int r = 0; r < int(R); r++) scanf( %s , gd[r]);     S = M + F + 1;     for (int i = 0; i < int(S); i++) {       scayger& s = sg[i];       scanf( %d%d%d , &s.r, &s.c, &s.t);       s.r--;       s.c--;       if (i == 0)         s.g = 0;       else if (i <= M)         s.g = 1;       else         s.g = 2;     }     memset(fw, -1, sizeof fw);     for (int r = 0; r < int(R); r++)       for (int c = 0; c < int(C); c++)         if (gd[r][c] ==  . ) {           for (int i = 0; i < int(4); i++) {             int r2 = r + dr[i], c2 = c + dc[i];             if (r2 < 0 || r2 >= R || c2 < 0 || c2 >= C || gd[r2][c2] ==  # )               continue;             fw[r][c][r2][c2] = fw[r2][c2][r][c] = 1;           }           fw[r][c][r][c] = 0;         }     for (int kr = 0; kr < int(R); kr++)       for (int kc = 0; kc < int(C); kc++)         if (gd[kr][kc] ==  . )           for (int ir = 0; ir < int(R); ir++)             for (int ic = 0; ic < int(C); ic++)               if (gd[ir][ic] ==  . )                 for (int jr = 0; jr < int(R); jr++)                   for (int jc = 0; jc < int(C); jc++)                     if (gd[jr][jc] ==  . ) {                       int &d1 = fw[ir][ic][kr][kc], &d2 = fw[kr][kc][jr][jc],                           &d = fw[ir][ic][jr][jc];                       if (d1 == -1 || d2 == -1) continue;                       if (d == -1 || d1 + d2 < d) d = d1 + d2;                     }     if (S % 2 != 0 || !tryit(LLONG_MAX)) {       puts( -1 );       return 0;     }     long long t0 = -1, t1 = 1000000000LL * R * C;     while (t1 - t0 > 1) {       long long t = (t0 + t1) / 2;       if (tryit(t))         t1 = t;       else         t0 = t;     }     printf( %lld n , t1);   }   