ghicitoare

#include <bits/stdc++.h>
using namespace std;

ifstream fin (“ghicitoare.in”);
ofstream fout (“ghicitoare.out”);
#define cin fin
#define cout fout

int n, x, T, k;

int xor_n (int n)
{ switch(n % 4){ case 0: return n; break; case 1: return 1; break; case 2: return n + 1; break; case 3: return 0; break; }

}

int main()
{ cin >> T; while(T—){ cin >> n >> k; x = xor_n(n); x ^= k; cout << x << “\n”; } return 0;

}