#include<bits/stdc++.h>
using namespace std;
using LL = long long;
using ULL = unsigned long long;
#define rep(i,n) for(int i=0; i<(n); i++)

int main() {
 string A,B; cin>>A>>B;
 reverse(A.begin(),A.end());
 reverse(B.begin(),B.end());
 vector<int> dA,dB;
 for(char c:A) dA.push_back(c-'0');
 for(char c:B) dB.push_back(c-'0');
 vector<int> xA,xB;
 while(dA.size()){
  xA.push_back(dA[0]%2);
  rep(i,dA.size()){
   if(dA[i]%2==1) if(i!=0) dA[i-1]+=5;
   dA[i]/=2;
  }
  if(dA.back()==0) dA.pop_back();
 }
 while(dB.size()){
  xB.push_back(dB[0]%2);
  rep(i,dB.size()){
   if(dB[i]%2==1) if(i!=0) dB[i-1]+=5;
   dB[i]/=2;
  }
  if(dB.back()==0) dB.pop_back();
 }

 xA.resize(4000); xB.resize(4000);
 rep(i,4000) xA[i]^=xB[i];

 reverse(xA.begin(),xA.end());

 vector<int> ans;
 rep(i,4000){
  int crr=0;
  rep(j,ans.size()){ ans[j]=ans[j]*2+crr; crr=ans[j]/10; ans[j]%=10; }
  if(crr) ans.push_back(crr);
  crr=xA[i];
  rep(j,ans.size()){ ans[j]=ans[j]+crr; crr=ans[j]/10; ans[j]%=10; }
  if(crr) ans.push_back(crr);
 }

 if(ans.size()==0) ans.push_back(0);
 reverse(ans.begin(),ans.end());
 for(int a:ans) cout<<a; cout<<endl;

 return 0;
}