func_code_string: #include <bits/stdc++.h>   using namespace std;   unsigned int inet4[100010];   int main(int argc, char* argv[]) {     ios_base::sync_with_stdio(false);     int n, m;     scanf( %d%d , &n, &m);     for (int i = 0; i < n; i++) {       char* str;       int inet[4];       scanf( %d.%d.%d.%d , &inet[0], &inet[1], &inet[2], &inet[3]);       inet4[i] = 0;       for (int j = 0; j < 4; j++) inet4[i] = inet4[i] * 256 + inet[j];     }     unsigned int mask = 0x80000000;     bool flag = false;     for (int i = 1; i < 32; i++) {       set<int> hh;       for (int j = 0; j < n; j++) {         hh.insert(inet4[j] & mask);       }       if (hh.size() == m) {         int ans[4];         for (int j = 3; j >= 0; j--) {           ans[j] = mask % 256;           mask /= 256;         }         printf( %d.%d.%d.%d n , ans[0], ans[1], ans[2], ans[3]);         flag = true;         break;       }       mask = mask | (mask >> 1);     }     if (!flag) printf( -1 n );     return 0;   }   