#include<bits/stdc++.h>
using namespace std;
const int N=1e5+10;
vector<int> side[N];
int a[N],na[N];
//point's weight
int n,m;
int epoch[N],t;

set<pair<int,int>>mp;
vector<int> side2[N];

void nside(){
	for(int i=1;i<=n;++i)
		for(auto &j:side[i])
			if(epoch[i]!=epoch[j] && mp.find({epoch[i],epoch[j]})==mp.end()){
				side2[epoch[i]].push_back(epoch[j]);
				mp.insert({epoch[i],epoch[j]});
			}
	for(int i=1;i<=n;++i)
		na[epoch[i]]+=a[i];
		return;
}

void dfs(int x){
	epoch[x]=++t;
	for(auto &i:side[x]){
		if(!epoch[i])dfs(i);
		epoch[x]=min(epoch[x],epoch[i]);
	}
	t--;
	return;
}

void dfs2(int x){
	int c=0;
	for(auto &i:side2[x]){
		dfs2(i);
		c=max(c,na[i]);
	}
	na[x]+=c;
	return;
}

void work(){
	cin>>n>>m;
	for(int i=1;i<=n;++i)
		cin>>a[i];
	for(int i=1;i<=m;++i){
		int x,y;cin>>x>>y;
		side[x].push_back(y);
	}
	for(int i=1;i<=n;++i)
		if(!epoch[i])dfs(i);
	//some point won't be dfsed because maybe m<n
	//there is not a complete tree
	nside();
	//max
	for(int i=1;i<=n;++i)
		dfs2(i);
	int ans=0;
	for(int i=1;i<=n;++i)
		ans=max(ans,na[i]);
	cout<<ans;
	return;
}

int main(){
	ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
	int _=1;
	while(_--)work();
	PROCESS_MEMORY_COUNTERS pmc1;
	return 0;
}