func_code_string: #include <bits/stdc++.h>   using namespace std;   long long int inf = 1e9 + 7;   int main() {     long long int n;     cin >> n;     vector<pair<long long int, long long int> > arr(n + 1);     for (long long int i = 1; i < n + 1; i++) {       long long int a, b;       cin >> a >> b;       arr[i].first = a;       arr[i].second = b;     }     vector<long long int> ans(n + 1);     ans[1] = 1;     long long int x, y;     x = arr[1].first;     y = arr[1].second;     if (arr[x].first == y or arr[x].second == y) {       ans[2] = x;       ans[3] = y;       long long int i = 3;       while (i != n) {         i++;         long long int a = arr[ans[i - 2]].first;         long long int b = arr[ans[i - 2]].second;         ans[i] = (a == ans[i - 1] ? b : a);       }       for (int i = 1; i < ans.size(); i++) {         cout << ans[i] <<    ;       }       return 0;     } else {       ans[2] = y;       ans[3] = x;       long long int i = 3;       while (i != n) {         i++;         long long int a = arr[ans[i - 2]].first;         long long int b = arr[ans[i - 2]].second;         ans[i] = (a == ans[i - 1] ? b : a);       }       for (int i = 1; i < ans.size(); i++) {         cout << ans[i] <<    ;       }       return 0;     }     return 0;   }   