func_code_string: #include <bits/stdc++.h>   using namespace std;   using ll = long long;   int n, m, chk[100100], a[100100], b[100100];   vector<int> v[100100];   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cin >> n >> m;     for (int i = 1; i <= m; i++) {       int a, b;       cin >> a >> b;       v[a].push_back(b), v[b].push_back(a);     }     for (int i = 1; i <= n; i++)       if (v[i].size() != n - 1) {         chk[i] = 1;         for (int x : v[i]) chk[x] = 1;         int j = 1, c = 0;         while (chk[j]) j++;         for (int k = 1; k <= n; k++)           if (k != i && k != j) a[k] = b[k] = ++c;         a[i] = b[i] = b[j] = ++c;         a[j] = ++c;         cout <<  YES n ;         for (int i = 1; i <= n; i++) cout << a[i] <<    ;         cout <<   n ;         for (int i = 1; i <= n; i++) cout << b[i] <<    ;         cout <<   n ;         return 0;       }     cout <<  NO ;   }   