func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, m;   int ans;   int a[400050];   int back[400050];   vector<int> edge[400050];   int main() {     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, u, v; i <= m; i++) {       cin >> u >> v;       edge[v].push_back(u);     }     for (auto iter : edge[a[n]]) back[iter]++;     for (int i = n - 1; i >= 1; i--) {       if (back[a[i]] == n - i - ans)         ans++;       else {         for (auto iter : edge[a[i]]) back[iter]++;       }     }     cout << ans << endl;     return 0;   }   