int dfs(int now,int flow,int sum)

 {

     if(now==n) return flow;

     for(int i=fir[now];i && (flow>sum);i=nex[i])

         if(d[to[i]]==d[now]+ && flo[i])

             zl=dfs(to[i],min(flow,flo[i]),),sum+=zl,flo[i]-=zl,flo[i^]+=zl;

     if(sum==) d[now]=;

     return sum;

 }

 bool bfs()

 {

     for(int i=;i<=n;i++) d[i]=;

     for(h=,t=,l[]=,d[]=;h<=t;h++)

         for(int i=fir[l[h]];i;i=nex[i])

             if(!d[to[i]] && flo[i])

                 l[++t]=to[i],d[l[t]]=d[l[h]]+;

     return d[n];

 }

 for(ans=;bfs();ans+=dfs(,INF,));