namespace flow { const int maxm = 1e5 + 5, maxn = 1e5 + 5, inf = 1e9; struct edge { int nxt, to, f; } e[maxm]; int cnt = 1, source, sink; int d[maxn], h[maxn], iter[maxn]; void link(int u, int v, int f) { e[++cnt].nxt = h[u]; h[u] = cnt; e[cnt].to = v; e[cnt].f = f; } void insert(int u, int v, int f) { link(u, v, f); link(v, u, 0); } void init() { memset(h, 0, sizeof(h)); cnt = 1; source = sink = 0; } bool bfs() { queue<int> q; memset(d, -1, sizeof(d)); d[source] = 0; q.push(source); while(!q.empty()) { int u = q.front(); q.pop(); for(int i = h[u]; i; i = e[i].nxt) if(d[e[i].to] == -1 && e[i].f) { d[e[i].to] = d[u] + 1; q.push(e[i].to); } } return ~d[sink]; } int dfs(int u, int f) { if(u == sink) return f; int ret = 0; for(int &i = iter[u]; i && f; i = e[i].nxt) if(d[e[i].to] == d[u] + 1 && e[i].f) { int x = dfs(e[i].to, min(f, e[i].f)); ret += x; f -= x; e[i].f -= x; e[i ^ 1] += x; } return ret; } int dinic() { int ret = 0; while(bfs()) { for(int i = 0; i < maxn; ++i) iter[i] = h[i]; ret += dfs(source, inf); } return ret; } }