AC code:

#include<bits/stdc++.h>
using namespace std;
int main(){
	int a,b,c,d;
	cin>>a>>b;
	do{
		c=a^b;
		d=(a&b)<<1;
		a=c;
		b=d;
	}while(b!=0);
	cout<<a;
	return 0;
}