#include #define rep(i,n) for(int i = 0; i < (n); ++i) #define srep(i,s,t) for (int i = s; i < t; ++i) #define drep(i,n) for(int i = (n)-1; i >= 0; --i) using namespace std; typedef long long int ll; typedef pair P; #define yn {puts("Yes");}else{puts("No");} #define MAX_N 200005 int main() { ll x, y, z, n; cin >> x >> y >> n; z = x ^ y; if(n % 3 == 0)cout << x << endl; if(n % 3 == 1)cout << y << endl; if(n % 3 == 2)cout << z << endl; return 0; }