struct Edge { int to, rev; ll f, c; }; vector> adj; int s, t; vector pt, dist; void addEdge(int u, int v, ll c) { adj[u].push_back({v, (int)ssize(adj[v]), 0, c}); adj[v].push_back({u, (int)ssize(adj[u]) - 1, 0, 0}); } bool bfs(ll lim) { dist.assign(ssize(adj), -1); dist[s] = 0; queue q({s}); while (!q.empty() && dist[t] < 0) { int v = q.front(); q.pop(); for (Edge& e : adj[v]) { if (dist[e.to] < 0 && e.c - e.f >= lim) { dist[e.to] = dist[v] + 1; q.push(e.to); }}} return dist[t] >= 0; } ll dfs(int v, ll flow) { if (v == t || flow == 0) return flow; for (; pt[v] < ssize(adj[v]); pt[v]++) { Edge& e = adj[v][pt[v]]; if (dist[e.to] != dist[v] + 1) continue; ll cur = dfs(e.to, min(e.c - e.f, flow)); if (cur > 0) { e.f += cur; adj[e.to][e.rev].f -= cur; return cur; }} return 0; } ll maxFlow(int source, int target) { s = source, t = target; ll flow = 0; // lim = 1 may be faster if capacities are small for (ll lim = (1LL << 62); lim >= 1; lim /= 2) { while (bfs(lim)) { pt.assign(ssize(adj), 0); ll cur; do { cur = dfs(s, lim); flow += cur; } while (cur > 0); }} return flow; }