#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<vector>
#include<cmath>
#include<algorithm>
#include<map>
#include<queue>
#include<deque>
#include<iomanip>
#include<tuple>
#include<cassert>
using namespace std;
typedef long long int LL;
typedef pair<int,int> P;
typedef pair<LL,int> LP;
const int INF=1<<30;
const LL MAX=1e9+7;

void array_show(int *array,int array_n,char middle=' '){
	for(int i=0;i<array_n;i++)printf("%d%c",array[i],(i!=array_n-1?middle:'\n'));
}
void array_show(LL *array,int array_n,char middle=' '){
	for(int i=0;i<array_n;i++)printf("%lld%c",array[i],(i!=array_n-1?middle:'\n'));
}
void array_show(vector<int> &vec_s,int vec_n=-1,char middle=' '){
	if(vec_n==-1)vec_n=vec_s.size();
	for(int i=0;i<vec_n;i++)printf("%d%c",vec_s[i],(i!=vec_n-1?middle:'\n'));
}
void array_show(vector<LL> &vec_s,int vec_n=-1,char middle=' '){
	if(vec_n==-1)vec_n=vec_s.size();
	for(int i=0;i<vec_n;i++)printf("%lld%c",vec_s[i],(i!=vec_n-1?middle:'\n'));
}

string sa,sb;
vector<int> v[5];

int main(){
	int n,m;
	int i,j,k;
	int a,b,c;
	cin>>sa>>sb;
	if(sa.size()>sb.size() || sa>sb)swap(sa,sb);
	for(char ca:sa){
		v[0].push_back((int)ca-(int)'0');
	}
	for(char ca:sb){
		v[1].push_back((int)ca-(int)'0');
	}
	v[2].push_back(0);
	bool flag=true;
	while(flag){
		a=v[0].back()%2,b=v[1].back()%2;
		v[3].push_back(a^b);
		for(i=0;i<2;i++){
			for(j=0,k=0;j<v[i].size();j++){
				if(v[i][j]%2==1 && j+1<v[i].size())v[i][j+1]+=10;
				v[i][j]/=2;
				if(v[i][j]==0)k++;
			}
		}
		if(k==v[1].size())break;
	}
	reverse(v[3].begin(),v[3].end());
	for(auto num:v[3]){
		for(auto& nim:v[2]){
			nim*=2;
		}
		v[2][0]+=num;
		for(i=0;i+1<v[2].size();i++){
			if(v[2][i]>=10){
				v[2][i+1]+=v[2][i]/10;
				v[2][i]%=10;
			}
		}
		a=v[2].back();
		if(a>=10){
			v[2].back()%=10;
			v[2].push_back(a/10);
		}
	}
	for(auto num:v[2]){
		cout<<(char)((int)'0'+num);
	}
	cout<<endl;
}