【HDU4289】

 int n,m; Max_Flow<int> MF;int main(){    freopen("in.txt","r",stdin);    //freopen("out.txt","w",stdout);    while(scanf("%d%d",&n,&m) != EOF){int S,T;scanf("%d%d",&S,&T);MF.Init(2*n+2,S,T+n);for(int i=1;i<=n;i++){int num;scanf("%d",&num);MF.Add_edge(i,i+n,num);}for(int i=0;i<m;i++){int u,v;scanf("%d%d",&u,&v);MF.Add_edge(u+n,v,0x3f3f3f3f);MF.Add_edge(v+n,u,0x3f3f3f3f);}printf("%d\n",MF.Dinic());}     return 0;}