dinic

#include<stdio.h> 
#define Max_vertex 10240 
#define Max_Edge 1024000 
#define Inf 0x7fffffff 
int To_Node[Max_Edge],Start_Node[Max_Edge],next[Max_Edge],Capacity[Max_Edge]; 
int Start[Max_vertex],Label[Max_vertex],Queue[Max_vertex]; 
int Source,Sink,Node_Num,Edge_Init,N,M; 
int min(int x,int y){ 
	if(x<y) 
		return x; 
	else  
		return y; 
}

void __insert(int from,int to ,int capacity){//initialize every edge with its capacity 
    Edge_Init++; 
    Capacity[Edge_Init]=capacity; 
    To_Node[Edge_Init]=to; 
    Start_Node[Edge_Init]= from; 
    next[Edge_Init]=Start[from]; 
    Start[from]=Edge_Init; 
}

void insert(int from,int to,int capacity){//initialize every edge and its reverse edge 
    __insert(from,to,capacity); 
    __insert(to,from,0); 
} 
 
int breath_first_seach(){//find shortest path and label every layer 
    int Top,Tail,edge,u,v,i; 
    Top=Tail=0; 
    Queue[Tail++]=Source; 
  	for(i=0; i<=Node_Num; i++) 
  		Label[i] =0; 
    Label[Source]=1; 
    while(Top<Tail){ 
        u=Queue[Top++]; 
        for(edge=Start[u]; edge!=-1; edge=next[edge]){ 
            v=To_Node[edge]; 
            if(Label[v]==0 && Capacity[edge]>0){ 
                Label[v]=Label[u]+1; 
                Queue[Tail++]=v; 
            } 
        } 
    } 
    return Label[Sink]; 
} 
 
int depth_first_search(int u,int  flow){//find an augmenting path 
	if( u == Sink)	return flow; 
	int t,edge,v, nowflow = 0; 
	for(edge = Start[u]; edge!=-1 && nowflow<flow; edge=next[edge]){ 
		v = To_Node[edge]; 
		if(Capacity[edge]>0 && Label[v] == Label[u] + 1){ 
			if(t = depth_first_search(To_Node[edge], min(Capacity[edge],flow-nowflow))){ 
				Capacity[edge] -= t; 
				Capacity[edge^1] += t; 
				nowflow += t; 
			} 
		} 
	}  
	if(!nowflow) Label[u] = -1; 
	return nowflow; 
} 
 
int dinic(){//Use dinic to solve Maximum flow problem  
	int flow=0, nowflow; 
	while(breath_first_seach()){ 
		nowflow = depth_first_search(Source,Inf); 
		flow = flow + nowflow; 
	} 
	return flow; 
} 
 
void init(int all,int from,int to){//Initialize Start & End, and very edge 
      int i; 
      Edge_Init=-1; 
      Node_Num=all; 
      Source=from;Sink=to; 
      for( i=0; i<=Node_Num; i++) 
      	Start[i] =-1; 
} 
 
int main(){ 
	int i,j,k,x,y,z; 
	scanf("%d%d", &N,&M); 
	init(N+4,0,N+2); 
	for(i=1; i<=N; i++){ 
		scanf("%d%d",&x,&y); 
		insert(Source,i,x); 
		insert(i,Sink,y); 
	} 
	for(i=0; i<M;i++){ 
		scanf("%d%d%d", &x,&y,&z); 
		insert(x,y,z); 
		insert(y,x,z); 
	} 
	int ans=dinic(); 
	printf("%d\n",ans); 
}