func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long N = 500500;   long long i, j, k, n, sum, ch, t, ans, num;   long long a[N], b[N], c[N];   void R(long long &x) {     x = 0;     ch = getchar();     while (ch <  0  ||  9  < ch) ch = getchar();     while ( 0  <= ch && ch <=  9 ) x = x * 10 + ch -  0 , ch = getchar();   }   int main() {     R(n);     for (i = 1; i <= n; i++) {       R(a[i]);       R(b[i]);       c[i] = a[i] ^ b[i];       sum ^= a[i];     }     k = 60;     for (i = 1; i <= n; i++) {       for (j = i + 1; j <= n; j++)         if (c[i] < c[j]) t = c[i], c[i] = c[j], c[j] = t;       if (!c[i]) break;       while (!(c[i] & 1ll << k)) k--;       for (j = i + 1; j <= n; j++)         if (c[j] & 1ll << k) c[j] ^= c[i];     }     num = i - 1;     ans = 1ll << num;     j = 60;     for (i = 1; i <= num; i++) {       while (!(c[i] & 1ll << j)) j--;       if (sum & 1ll << j) sum ^= c[i];     }     if (sum)       puts( 1/1 );     else       printf( %I64d/%I64d n , ans - 1, ans);   }   