func_code_string: #include <bits/stdc++.h>   using namespace std;   int main(void) {     ios::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     int n, m;     cin >> n >> m;     if (n <= 450 and m == n * (n - 1) / 2) {       cout <<  NO n ;       return 0;     }     vector<set<int>> g(n + 1);     for (int i = 0; i < m; ++i) {       int u, v;       cin >> u >> v;       g[u].insert(v);       g[v].insert(u);     }     int x = -1, y = -1;     for (int i = 1; i <= n and x == -1; ++i) {       if ((int)g[i].size() == n - 1) continue;       for (int j = 1; j <= n and x == -1; ++j) {         if (i == j) continue;         if (g[i].find(j) == g[i].end()) tie(x, y) = tie(i, j);       }     }     vector<int> v1, v2;     int cur = 3;     for (int i = 1; i <= n; ++i) {       if (i == x) {         v1.push_back(1);         v2.push_back(1);       } else if (i == y) {         v1.push_back(2);         v2.push_back(1);       } else {         v2.push_back(cur);         v1.push_back(cur++);       }     }     cout <<  YES n ;     for (auto x : v1) cout << x <<    ;     cout <<   n ;     for (auto x : v2) cout << x <<    ;   }   