func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 3e4 + 5;   map<int, int> mp[N];   int arr[N];   int main() {     int n, m, a, b;     cin >> n >> m;     while (m--) {       cin >> a >> b;       mp[a][b]++;     }     arr[1] = 1;     for (int i = 2; i <= n; i++) {       int j = i;       arr[j] = j;       while (j > 1 && mp[arr[j - 1]][arr[j]] == 1) {         swap(arr[j], arr[j - 1]);         j--;       }     }     for (int i = 1; i <= n; i++) {       cout << arr[i] <<    ;     }     cout << endl;     return 0;   }   