func_code_string: #include <bits/stdc++.h>   using namespace std;   long long n, m, s, t, k, a, b, x, y, u;   const int mod = 1e9 + 7;   const int mxn = 2e5 + 5;   long long mn = 1e18, mx = 0;   long long arr[2000000], wan[2000000], finl[2000000];   string str, str2;   vector<vector<long long> > v(200000), cm(200000);   map<long long, long long> mp, pm;   map<pair<long long, long long>, long long> frq;   int main() {     ios_base::sync_with_stdio(0);     t = 1;     while (t--) {       cin >> n;       long long z;       for (int i = 0; i < n - 2; i++) {         cin >> x >> y >> z;         mp[x]++;         mp[y]++;         mp[z]++;         frq[{x, y}]++, frq[{y, x}]++;         if (frq[{x, y}] == 2) cm[x].push_back(y), cm[y].push_back(x);         frq[{x, z}]++, frq[{z, x}]++;         if (frq[{x, z}] == 2) cm[x].push_back(z), cm[z].push_back(x);         frq[{z, y}]++, frq[{y, z}]++;         if (frq[{z, y}] == 2) cm[z].push_back(y), cm[y].push_back(z);       }       for (int i = 1; i <= n; i++) {         if (mp[i]) {           v[mp[i]].push_back(i);         }       }       int l = 0;       for (int i = 1; i <= 2; i++) {         long long fr = 0, se = 0;         long long valf = 0, vals = 0;         int j = 0;         for (auto it : v[i]) {           if (i == 1) {             arr[l++] = it;             pm[it]++;             break;           } else {             if (!j)               fr = frq[{arr[l - 1], it}], valf = it;             else               se = frq[{arr[l - 1], it}], vals = it;             j++;           }         }         if (i != 1) {           if (fr > se) {             arr[l++] = valf;             pm[valf]++;           } else             arr[l++] = vals, pm[vals]++;           ;         }       }       for (int i = 0; i < l; i++) cout << arr[i] <<    ;       long long cn = n - 4;       while (cn) {         for (auto i : cm[arr[l - 1]]) {           if (!pm[i]) {             pm[i] = 1;             cout << i <<    ;             arr[l++] = i;           }         }         cn--;       }       for (int i = 2; i >= 1; i--) {         for (auto it : v[i]) {           if (!pm[it]) {             cout << it <<    ;           }         }       }     }     return 0;   }   