rt 跪求调，在线等

#include <bits/stdc++.h>
using namespace std;
const int N = 1e4 + 10;
const int M = 1e5 + 10;
int n, m, cnt, ans;
int a[N], dp[N];
int head[N], to[M], nxt[M];
int head2[N], to2[M], nxt2[M], in[N];
int dfn[N], vis[N], low[N];
int top, sta[N];
int point[N];

void add1(int x, int y)
{
    cnt++;
    nxt[cnt] = head[x];
    to[cnt] = y;
    head[x] = cnt;
}

void add2(int x, int y)
{
    cnt++;
    nxt2[cnt] = head[x];
    to2[cnt] = y;
    head2[x] = cnt;
}

void Tarjan(int x)
{
    dfn[x] = low[x] = ++cnt;
    vis[x] = 1, sta[++top] = x;
    for(int i = head[x]; i; i = nxt[i])
    {
        if(!dfn[to[i]])
        {
            Tarjan(to[i]);
            low[x] = min(low[x], low[to[i]]);
        }
        else if(vis[to[i]])
        {
            low[x] = min(low[x], low[to[i]]);
        }
    }
    if(low[x] == dfn[x])
    {
        vis[x] = 0;
        point[x] = x;
        while(sta[top] != x)
        {
            int y = sta[top];
            vis[y] = 0;
            a[x] += a[y];
            point[y] = x;
            top--;
        }
        top--;
    }
}

void top_sort()
{
    stack<int> s;
    for(int i = 1; i <= n; i++)
    {
        if(i == point[i] && in[i] == 0) s.push(i), dp[i] = a[i];
    }
    while(!s.empty())
    {
        int h = s.top();
        s.pop();
        for(int i = head2[h]; i; i = nxt2[i])
        {
            dp[to2[i]] = max(dp[to2[i]], dp[h] + a[to2[i]]);
            in[to2[i]]--;
            if(!in[to2[i]]) s.push(to2[i]);
        }
    }
}

int main()
{
    std::ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);
    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;
        add1(x, y);
    }
    cnt = 0;
    for(int i = 1; i <= n; i++)
    {
        if(!dfn[i]) Tarjan(i);
    }
    cnt = 0;
    for(int i = 1; i <= n; i++)
    {
        for(int j = head[i]; j; j = nxt[j])
        {
            int x = point[i];
            int y = point[to[j]];
            add2(x, y);
            in[y]++;
        }
    }
    top_sort();
    for(int i = 1; i <= n; i++)
    {
        ans = max(ans, dp[i]);
    }
    cout << ans << "\n";
    return 0;
}