func_code_string: #include <bits/stdc++.h>   using namespace std;   map<int, int> Map;   int n, m, i, j;   long long ans;   string s;   int main() {     cin >> n;     for (i = 1; i <= n; i++) {       cin >> s;       m = s.size();       bool cnt[30];       for (j = 0; j < 26; j++) cnt[j] = 0;       for (j = 0; j < m; j++) cnt[s[j] -  a ] ^= 1;       int aux1 = 0;       for (j = 0; j < 26; j++) {         aux1 <<= 1;         aux1 |= cnt[j];       }       for (j = 0; j < 26; j++) ans += Map[aux1 ^ (1 << j)];       ans += Map[aux1];       Map[aux1]++;     }     cout << ans;     return 0;   }   