#include using namespace std; #define lo long long #define sr string #define ch char #define ve vector #define al(x) x.begin(),x.end() #define sort(x) sort(x.begin(),x.end()) #define reverse(x) reverse(x.begin(),x.end()) #define rep(i,a) for(lo i=0;i=b;i--) #define wh while int main(){ lo a,b; cin>>a>>b; cout<<(a^b)<