#include <bits/stdc++.h>

using namespace std;

#define N 1010
#define pb push_back

int fa[N];
int v[N];
vector<int> e[N];
int len[N];
int mi[N];
int ans;

void dfs(int r, int l)
{
    len[r] = l + v[r];
    if (e[r].size() == 0)
    {
        mi[r] = len[r];
        return;
    }
    vector<int> temp;
    for (int i = 0; i < e[r].size(); i++)
    {
        dfs(e[r][i], l + v[r]);
        mi[r] = min(mi[r], mi[e[r][i]]);
        temp.pb(mi[e[r][i]]);
    }
    if (e[r].size() > 1)
    {
        sort(temp.begin(), temp.end());
        ans = min(ans, temp[temp.size() - 1] + temp[temp.size() - 2] - len[r]);
    }
}

int main()
{
    int n, m;
    scanf("%d%d", &n, &m);
    mi[0] = N;
    for (int i = 1; i <= n; i++)
    {
        scanf("%d", &v[i]);
        mi[i] = N;
    }
    for (int i = 0; i < m; i++)
    {
        int a, b;
        scanf("%d%d", &a, &b);
        fa[b] = a;
    }
    for (int i = 1; i <= n; i++)
    {
        e[fa[i]].pb(i);
    }
    ans = N * N;
    dfs(0, 0);

    printf("%d\n", ans);

    return 0;
}