#include<bits/stdc++.h>
using namespace std;

int dq[10005],ss[10005],tme,dfn[10005],low[10005],eq[10005],rd[10005],dp[10005],n,v[10005];
vector<int>a[10005],b[10005],xtd;
stack<int>qwq;
int find(int x)
{
	if(ss[x]==0||ss[x]==x)
	{
		return ss[x]=x;
	}
	return find(ss[x]);
}
void dfs(int x)
{
    tme++;
    dfn[x]=low[x]=tme;
    qwq.push(x);
    v[x]=1;
    for(int i=0;i<a[x].size();i++)
    {
        if(!dfn[a[x][i]])
        {
            dfs(a[x][i]);
            low[x]=min(low[x],low[a[x][i]]);
        }else
        {
            if(v[a[x][i]]==1)
            {
                low[x]=min(low[x],low[a[x][i]]);
            }
        }
    }
    if(dfn[x]==low[x])
    {
        while(v[x]!=2)
        {
            ss[find(qwq.top())]=find(x);
            v[qwq.top()]=2;
            qwq.pop();
        }
    }
}
inline void xt()
{
    for(int i=1;i<=n;i++)
    {
    	eq[find(ss[i])]+=dq[i];
        for(int j=0;j<a[i].size();j++)
        {
            if(find(ss[i])!=find(ss[a[i][j]]))
            {
                b[find(ss[i])].push_back(find(ss[a[i][j]]));
                rd[find(ss[i])]++;
            }
        }
    }
}
inline int tp()
{
    queue<int>q;
    int maxn=0;
    for(int i=1;i<=n;i++)
    {
        if(!rd[i]&&find(ss[i])==i)
        {
            q.push(i);
            dp[i]=eq[i];
        }
    }
    while(q.size())
    {
        maxn=max(maxn,dp[q.front()]);
        for(int i=0;i<b[q.front()].size();i++)
        {
            dp[b[q.front()][i]]=max(dp[b[q.front()][i]],dp[q.front()]+eq[b[q.front()][i]]);
            rd[b[q.front()][i]]--;
            if(!rd[b[q.front()][i]])
            {
                q.push(b[q.front()][i]);
            }
        }
        q.pop();
    }
    return maxn;
}
int main()
{
    int m;
    cin>>n>>m;
    for(int i=1;i<=n;i++)
    {
        cin>>dq[i];
    }
    while(m--)
    {
        int x,y;
        cin>>x>>y;
        a[x].push_back(y);
    }
    for(int i=1;i<=n;i++)
    {
        if(!dfn[i])
        {
            dfs(i);
        }
    }
    xt();
    cout<<tp();
    return 0;
}