func_code_string: #include <bits/stdc++.h>   using namespace std;   vector<int> disp[500][500];   int n, m, a, b;   int pos[4][2] = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};   class edge {    public:     int e, nxt, cap;     edge(int e1 = -1, int nxt1 = -1, int cap1 = 0) {       e = e1, nxt = nxt1, cap = cap1;     }   };   int S, T;   int dep[1950];   bool vis[1950];   class graph {    public:     edge g[1000000];     int head[1950], tmpcnt;     int cur[1950];     void init() {       memset(head, 255, sizeof(head));       tmpcnt = 0;     }     void addedge(int s, int e, int cap) {       if (cap == 0) return;       g[tmpcnt] = edge(e, head[s], cap), head[s] = tmpcnt++;       g[tmpcnt] = edge(s, head[e], 0), head[e] = tmpcnt++;     }     bool bfs() {       memset(vis, 0, sizeof(vis));       memset(dep, 0, sizeof(dep));       queue<int> q;       q.push(S);       vis[S] = 1;       while (!q.empty()) {         int fr = q.front();         q.pop();         for (int i = head[fr]; i != -1; i = g[i].nxt) {           if (g[i].cap > 0 && !vis[g[i].e]) {             dep[g[i].e] = dep[fr] + 1;             vis[g[i].e] = 1;             q.push(g[i].e);           }         }       }       return vis[T];     }     int dfs(int np, int maxflow) {       int f;       int flow = 0;       if (np == T || !maxflow) return maxflow;       for (int i = cur[np]; i != -1; i = g[i].nxt) {         cur[np] = i;         if (g[i].cap > 0 && dep[g[i].e] == dep[np] + 1 &&             (f = dfs(g[i].e, min(g[i].cap, maxflow))) > 0) {           g[i].cap -= f;           g[i ^ 1].cap += f;           flow += f;           maxflow -= f;           if (!maxflow) break;         }       }       return flow;     }     int dinic() {       int out = 0;       while (bfs()) memcpy(cur, head, sizeof(cur)), out += dfs(S, 0x3f3f3f3f);       return out;     }   } G;   inline int id(int x, int y) { return (x - 1) * m + y; }   int dis[30][30];   char s[30][30];   void init(int x, int y) {     memset(dis, 255, sizeof(dis));     int st = id(x, y);     queue<pair<int, int> > q;     q.push(make_pair(x, y));     dis[x][y] = 0;     disp[st][0].push_back(st);     while (!q.empty()) {       pair<int, int> fr = q.front();       q.pop();       for (int i = 0; i < 4; i++) {         int nx = fr.first + pos[i][0], ny = fr.second + pos[i][1];         if (s[nx][ny] ==  .  && dis[nx][ny] == -1) {           dis[nx][ny] = dis[fr.first][fr.second] + 1;           disp[st][dis[nx][ny]].push_back(id(nx, ny));           q.push(make_pair(nx, ny));         }       }     }   }   class peo {    public:     int x, y, t;   } male[500], female[500];   int main() {     scanf( %d%d%d%d , &n, &m, &a, &b);     for (int i = 1; i <= n; i++) scanf( %s , s[i] + 1);     for (int i = 1; i <= n; i++) {       for (int j = 1; j <= m; j++) {         if (s[i][j] !=  # ) init(i, j);       }     }     if (b == a + 1) {       scanf( %d%d%d , &male[a + 1].x, &male[a + 1].y, &male[a + 1].t);     } else if (a == b + 1) {       scanf( %d%d%d , &female[b + 1].x, &female[b + 1].y, &female[b + 1].t);     } else {       puts( -1 );       return 0;     }     int K = max(a, b);     for (int i = 1; i <= a; i++)       scanf( %d%d%d , &male[i].x, &male[i].y, &male[i].t);     for (int i = 1; i <= b; i++)       scanf( %d%d%d , &female[i].x, &female[i].y, &female[i].t);     long long L = 0, R = 1ll << 40, ans = -1;     S = 2 * (K + n * m) + 1;     T = 2 * (K + n * m) + 2;     while (L <= R) {       long long mid = (L + R) >> 1;       G.init();       for (int i = 1; i <= K; i++) {         G.addedge(S, i + 2 * n * m, 1);         G.addedge(i + K + 2 * n * m, T, 1);         int pm = id(male[i].x, male[i].y);         for (int j = 0; j <= mid / male[i].t && j <= n * m; j++) {           for (auto &x : disp[pm][j]) G.addedge(i + 2 * n * m, x, 1);         }         pm = id(female[i].x, female[i].y);         for (int j = 0; j <= mid / female[i].t && j <= n * m; j++) {           for (auto &x : disp[pm][j]) G.addedge(x + n * m, i + K + 2 * n * m, 1);         }       }       for (int i = 1; i <= n * m; i++) G.addedge(i, i + n * m, 1);       if (G.dinic() != K)         L = mid + 1;       else         ans = mid, R = mid - 1;     }     printf( %lld n , ans);     return 0;   }   