func_code_string: #include <bits/stdc++.h>   using namespace std;   long long dp[55][2];   int main() {     long long X, Y;     scanf( %lld %lld , &Y, &X);     dp[51][0] = 1;     for (int i = 50; i >= 0; i--) {       for (int flag = 0; flag <= 1; flag++) {         bool x = (X >> i) & 1, y = (Y >> i) & 1;         if (x)           dp[i][flag] += dp[i + 1][(flag + 1) / 2] * (flag != y) * 2;         else {           dp[i][flag] += dp[i + 1][(flag + 2) / 2] * (flag == y);           dp[i][flag] += dp[i + 1][0] * (flag == y);         }       }     }     if (!X) assert(dp[0][0] - (X == Y) * 2 == (!(Y & 1)));     printf( %lld n , dp[0][0] - (X == Y) * 2);     return 0;   }   