void dijkstra(){
	priority_queue<pair<long long,int>,vector<pair<long long,int> >,greater<pair<long long,int> > >PQ;
	for (int i=0;i<N;i++)dist[i]=~0uLL>>2;
	dist[0]=0;
	PQ.push(make_pair(dist[0],0));
	while (!PQ.empty()){
		long long d=PQ.top().first;
		int a=PQ.top().second;
		PQ.pop();
		if (d!=dist[a])continue;
		for (edge *p=E[a];p;p=p->next)
			if (dist[p->e]>d+p->c)
				PQ.push(make_pair(dist[p->e]=d+p->c,p->e));
	}
}