func_code_string: #include <bits/stdc++.h>   using namespace std;   unsigned int ip[100005];   unsigned int const one = -1;   int main() {     int n, k;     cin >> n >> k;     for (int i = 0; i < n; i++) {       unsigned int a, b, c, d;       scanf( %u.%u.%u.%u , &a, &b, &c, &d);       ip[i] = (a << 24) + (b << 16) + (c << 8) + d;     }     unsigned int mask = 0;     set<unsigned int> S;     for (int i = 1; i < 32; i++) {       mask = one << (32 - i);       for (int j = 0; j < n; j++) {         S.insert(mask & ip[j]);       }       if (S.size() == k) {         unsigned int a, b, c, d;         a = mask >> 24;         b = (mask << 8) >> 24;         c = (mask << 16) >> 24;         d = (mask << 24) >> 24;         printf( %u.%u.%u.%u , a, b, c, d);         return 0;       }       S.clear();     }     cout << -1;     return 0;   }   