#include<iostream> #include<string> #include<algorithm> #include<vector> #include<queue> #include<map> #include<math.h> #include<iomanip> #include<set> #include<numeric> #include<cstring> #include<cstdio> #include<functional> #include<bitset> #include<limits.h> #include<cassert> #include<iterator> #include<complex> #include<stack> #include<sstream> using namespace std; typedef long long int lint; typedef pair<int, int> IP; typedef pair<lint, lint> LLP; typedef pair<char, char>CP; #define rep(i, n) for (int i = 0; i < n; i++) #define repr(i, n) for (int i = n; i >= 0; i--) #define sort(v) sort((v).begin(), (v).end()) #define reverse(v) reverse((v).begin(), (v).end()) #define upper(v,hoge) upper_bound(v.begin(),v.end(),hoge) #define lower(v,hoge) lower_bound(v.begin(),v.end(),hoge) #define llower(v,hoge) *lower_bound(v.begin(), v.end(), hoge) #define lupper(v,hoge) *upper_bound(v.begin(), v.end(), hoge) int main() { lint A, C; cin >> A >> C; lint B = C ^ A; cout << B << endl; }