func_code_string: #include <bits/stdc++.h>   using namespace std;   unordered_set<string> was;   int n, i, j, pos, k = 13, t;   string codes[1001];   int main() {     ios_base::sync_with_stdio(false);     cin >> n;     for (; i < n; ++i) cin >> codes[i];     for (i = 0; i < n; ++i)       for (j = i + 1; j < n; ++j) {         t = 0;         for (pos = 0; pos < 6; ++pos) t += codes[i][pos] != codes[j][pos];         k = min(k, t);       }     cout << (k - 1) / 2;     return 0;   }   