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

const int B = 60;
int sufl[B], sufg[B];
int prel[B], pree[B];

inline int bit(long long x, int p){
	return (x >> p) & 1;
}

inline void compute1(long long L, long long P){
	if(bit(L, 0)){
		sufl[0] = sufg[0] = bit(P, 0)^1;
	}else{
		sufl[0] = 1;
		sufg[0] = 0;
	}
	int nbits = bit(L, 0);
	for(int i = 1; i < B; i++){
		if(bit(P, i) == 0){
			sufl[i] = sufl[i - 1];
		}else if(bit(L, i) == 0){
			sufl[i] = 0;
			if(nbits == 0){
				sufl[i] ^= 1;
			}
		}else{
			sufl[i] = sufl[i - 1];
			if(nbits == 0){
				sufl[i] ^= 1;
			}
		}
		nbits += bit(L, i);
		if(nbits == 0){
			sufg[i] = sufl[i]^1;
		}else{
			sufg[i] = sufl[i];
		}
	}
}

inline void compute2(long long L, long long P){
	int cur = 1;
	for(int i = B - 1; i >= 0; i--){
		if(cur && bit(P, i) && !bit(L, i)){
			cur = 0;
		}
		pree[i] = cur;
	}

	if(bit(L, B - 1)){
		prel[B - 1] = bit(P, B - 1)^1;
	}else{
		prel[B - 1] = 1;
	}
	for(int i = B - 2; i >= 0; i--){
		if(bit(L, i)){
			if(bit(P, i)){
				prel[i] = 0;
			}else{
				prel[i] = pree[i + 1];
			}
		}else{
			prel[i] = prel[i + 1];
		}
	}
}

inline long long computeAnswer(long long L, long long P){
	compute1(L, P);
	compute2(L, P);
	long long ans = 0;
	for(int i = 0; i < B; i++){
		int nodd;
		int neve;
		if(i == B - 1){
			if(bit(P, i)){
				nodd = 1;
			}else{
				nodd = 0;
			}
			neve = 0;
		}else{
			if(bit(P, i)){
				if(bit(L, i)){
					neve = prel[i + 1]^pree[i + 1];
				}else{
					neve = 0;
				}
				nodd = prel[i + 1];
			}else{
				if(bit(L, i)){
					nodd = prel[i + 1]^pree[i + 1];
				}else{
					nodd = 0;
				}
				neve = prel[i + 1]^pree[i + 1];
			}
		}

		if(i == 0){
			if(nodd){
				ans ^= (1LL << i);
			}
		}else{
			int cnt = (nodd & sufl[i - 1])^(neve & sufg[i - 1]);
			if(cnt){
				ans ^= (1LL << i);
			}
		}
	}
	return ans;
}

inline long long brute(long long K, long long P){
	long long ret = 0;
	for(long long J = 1; J <= P; J++){
		if(((K + P - J)&K) == K){
			ret ^= J;
		}
	}
	return ret;
}

void stressTest(int BB){
	mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
	for(int i = 0; i < 100000; i++){
		cout << "Testing " << i << "-th round with ";
		int K = rng()&((1 << BB) - 1);
		int P = rng()&((1 << BB) - 1);
		cout << "K = " << K << " and P = " << P << endl;
		assert(brute(K, P) == computeAnswer(((1 << BB) - 1)^K, P));
	}
}

int main(){
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	// stressTest(20);

	int Q; cin >> Q;
	while(Q--){
		long long K; cin >> K;
		long long P; cin >> P;
		if(K == 0){
			cout << P << '\n';
			continue;
		}
		K--;
		long long L = ((1LL << B) - 1)^K;
		cout << computeAnswer(L, P) << '\n';
	}

	return 0;
}