func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 25;   const int maxm = 3000;   char maze[maxn][maxn];   int g[maxn * maxn][maxn * maxn];   int n, m, N, M;   int src, sink;   long long ans;   struct Node {     int r, c, t;     Node() {}     Node(int r, int c, int t) : r(r), c(c), t(t) {}   };   vector<Node> males, fmales;   struct Edge {     int u, v, c;     Edge() {}     Edge(int u, int v, int c) : u(u), v(v), c(c) {}   };   struct MaxFlow {     int n, m;     int Now[maxm], Dfn[maxm];     vector<Edge> edges;     vector<int> G[maxm];     void init(int n) {       this->n = n;       for (auto &x : G) x.clear();       edges.clear();     }     void add(int u, int v, int c) {       edges.push_back(Edge(u, v, c));       edges.push_back(Edge(v, u, 0));       m = ((int)((edges).size()));       G[u].push_back(m - 2);       G[v].push_back(m - 1);     }     int ISAP(int s, int flow) {       if (s == sink) return flow;       int v, tab = n, now = 0, vary;       for (int i = 0; i < ((int)((G[s]).size())); i++) {         Edge &e = edges[G[s][i]];         if (e.c > 0) {           if (Dfn[s] == Dfn[v = e.v] + 1)             vary = ISAP(v, min(flow - now, e.c)), now += vary, e.c -= vary,             edges[G[s][i] ^ 1].c += vary;           if (Dfn[src] == n) return now;           if (e.c > 0) tab = min(tab, Dfn[v]);           if (now == flow) break;         }       }       if (now == 0) {         if (--Now[Dfn[s]] == 0) Dfn[src] = n;         ++Now[Dfn[s] = tab + 1];       }       return now;     }     int getAns() {       int flow = 0;       memset(Dfn, 0, sizeof Dfn);       memset(Now, 0, sizeof Now);       Now[0] = n;       while (Dfn[src] < n) flow += ISAP(src, 0x0f0f0f0f);       return flow;     }   } solver;   int idx(char x, int y) { return x * m + y; }   bool cango(int x, int y) { return x >= 0 && x < n && y >= 0 && y < m; }   int dx[] = {0, 0, -1, 1};   int dy[] = {-1, 1, 0, 0};   void calDist() {     memset(g, 0x0f, sizeof g);     for (int i = 0; i < n * m; i++) g[i][i] = 0;     for (int x = 0; x < n; x++)       for (int y = 0; y < m; y++) {         if (maze[x][y] !=  . ) continue;         int u = idx(x, y);         for (int k = 0; k < 4; k++) {           int nx = x + dx[k];           int ny = y + dy[k];           if (!cango(nx, ny) || maze[nx][ny] ==  # ) continue;           int v = idx(nx, ny);           g[u][v] = 1;         }       }     for (int k = 0; k < n * m; k++)       for (int i = 0; i < n * m; i++)         for (int j = 0; j < n * m; j++) {           if (g[i][k] == 0x0f0f0f0f || g[k][j] == 0x0f0f0f0f) continue;           g[i][j] = min(g[i][j], g[i][k] + g[k][j]);         }   }   bool check(long long mid) {     src = 2 * N + 2 * n * m;     sink = src + 1;     solver.init(sink + 1);     for (int j = 0; j < n; j++)       for (int k = 0; k < m; k++) {         if (maze[j][k] ==  # ) continue;         int v = idx(j, k);         int id1 = 2 * N + v * 2;         int id2 = id1 + 1;         solver.add(id1, id2, 1);       }     for (int i = 0; i < N; i++) {       int x = males[i].r, y = males[i].c, t = males[i].t;       int u = idx(x, y);       solver.add(src, i, 1);       for (int j = 0; j < n; j++)         for (int k = 0; k < m; k++) {           if (maze[j][k] ==  # ) continue;           int v = idx(j, k);           int id1 = 2 * N + v * 2;           int id2 = id1 + 1;           if (g[u][v] != 0x0f0f0f0f && 1.0 * g[u][v] * t <= mid)             solver.add(i, id1, 1);         }       x = fmales[i].r, y = fmales[i].c, t = fmales[i].t;       u = idx(x, y);       solver.add(i + N, sink, 1);       for (int j = 0; j < n; j++)         for (int k = 0; k < m; k++) {           if (maze[j][k] ==  # ) continue;           int v = idx(j, k);           int id1 = 2 * N + v * 2;           int id2 = id1 + 1;           if (g[u][v] != 0x0f0f0f0f && 1.0 * g[u][v] * t <= mid)             solver.add(id2, i + N, 1);         }     }     return solver.getAns() == N;   }   int main() {     cin >> n >> m >> N >> M;     for (int i = 0; i < n; i++) scanf( %s , maze[i]);     int ok = 1;     int r, c, t;     scanf( %d%d%d , &r, &c, &t);     r--, c--;     if (N - M == 1) {       fmales.push_back(Node(r, c, t));     } else if (M - N == 1) {       males.push_back(Node(r, c, t));     } else {       ok = 0;     }     for (int i = 0; i < N; i++) {       scanf( %d%d%d , &r, &c, &t);       r--, c--;       males.push_back(Node(r, c, t));     }     for (int i = 0; i < M; i++) {       int r, c, t;       scanf( %d%d%d , &r, &c, &t);       r--, c--;       fmales.push_back(Node(r, c, t));     }     if (!ok) {       puts( -1 );       return 0;     }     N = max(N, M);     calDist();     long long L = 0, R = (long long)1e15;     while (R - L > 0) {       long long mid = (L + R) >> 1;       if (check(mid))         R = mid;       else         L = mid + 1;     }     if (R != (long long)1e15) {       printf( %lld n , R);     } else       puts( -1 );     return 0;   }   