func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, _m, ans = 0;   map<string, int> m;   string s[1010], u[1010], v[1010];   int main() {     cin >> n >> _m;     for (int i = 1; i <= n; i++) cin >> s[i];     sort(s + 1, s + n + 1);     for (int i = 1; i <= n; i++) m[s[i]] = i - 1;     for (int i = 1; i <= _m; i++) cin >> u[i] >> v[i];     for (int i = 1; i <= (1 << n); i++) {       bool flag = 1;       for (int j = 1; j <= _m; j++)         if (((i - 1) & (1 << m[u[j]])) && ((i - 1) & (1 << m[v[j]]))) flag = 0;       if (flag && __builtin_popcount(ans) < __builtin_popcount(i - 1))         ans = i - 1;     }     cout << __builtin_popcount(ans) <<   n ;     for (int i = 1; i <= n; i++)       if (ans & (1 << (i - 1))) cout << s[i] <<   n ;     return 0;   }   