//最短增廣路，Dinic演算法 
struct Edge
{
    int from,to,cap,flow;
};//弧度 

void AddEdge(int from,int to,int cap)  //增弧 
{
    edges.push_back((Edge){from,to,cap,0});
    edges.push_back((Edge){to,from,0,0});
    m=edges.size();
    G[from].push_back(m-2);
    G[to].push_back(m-1);
}


struct Dinic{
    int n,m,s,t;
    vector
 
<Edge> edges;
    vector<int> G[maxn];
    bool vis[maxn];
    int d[maxn];
    int cur[maxn]; 
    
    bool Bfs()   //構建分層網路 
    {
        memset(vis,0,sizeof(vis));
        queue<int> Q;
        Q.push(s);
        d[s]=0;
        vis[s]=1;
        while(!Q.empty())
        {
            
 
int x=Q.front();
                Q.pop();
            for(int i=0;i<G[x].size();i++)
            Edge& e=edges[G[x][i]];
            if(!vis[e.to]&&e.cap>e.flow)
            {
                vis[e.to]=1;
                d[e.to]=d[x]+1;
                Q.push(e.to);
            }
        }
        
 
return vis[t];
    }
};

int DFS(int x,int a)//沿阻塞流增廣 
{
    if(x==t||a==0)
    return a;
    int flow=0,f;
    for(int& i=cur[x];i<G[x].size();i++)
    {
        Edge& e=edges[G[x][i]];
        if(d[x]+1==d[e.to]&&(f=DFS(e.to,min(a,e.cap-e.flow)))>0)
        {
            e.flow+=f;
            edges[G[x][i]^1].flow-=f;
            flow+=f;
            a-=f;
            if(a==0)
            break;
        }
    }
    return flow;
}

int Maxflow(int s,int t)
{
    this->s=0;
    this->t=t;
    int flow=0;
    while(BFS())
    {
        memset(cur,0,sizeof(cur));
        flow+=DFS(s,inf);
    }
    return flow;
}