func_code_string: #include <bits/stdc++.h>   long long inp() {     char c = getchar();     int neg = 1;     while (c <  0  || c >  9 ) {       if (c ==  - ) neg = -1;       c = getchar();     }     long long sum = 0;     while (c >=  0  && c <=  9 ) {       sum = sum * 10 + c -  0 ;       c = getchar();     }     return sum * neg;   }   long long v[300010], mask[300010];   int main() {     int n = inp();     long long sum = 0;     for (int i = 1; i <= n; i++) {       v[i] = inp();       sum += v[i];       mask[i] = inp();     }     if (sum < 0)       for (int i = 1; i <= n; i++) v[i] *= -1;     long long s = 0;     for (int i = 0; i <= 61; i++) {       long long sum = 0;       for (int j = 1; j <= n; j++) {         if (mask[j] & (1ll << i)) {           if (mask[j] <= (1ll << (i + 1))) {             if (__builtin_popcountll(s & mask[j]) & 1)               sum += v[j];             else               sum -= v[j];           }         }       }       if (sum < 0) s |= (1ll << i);     }     std::cout << s << std::endl;   }   