#include <cstdio>

typedef long long LL;
const int Mod = 998244353;
const int MN = 10000005;

int Inv[MN];

inline void Init(int N) {
    Inv[1] = 1;
    for (int i = 2; i <= N; ++i)
        Inv[i] = (LL)(Mod - Mod / i) * Inv[Mod % i] % Mod;
}

int N, C;

inline void Solve() {
    scanf("%d%d", &N, &C);
    int coef1 = (2 * C + 2) % Mod;
    int coef2 = (LL)C * C % Mod * (Mod - 4) % Mod;
    int a0 = 0, a1 = 1, ans = 0;
    for (int i = 1; i <= N; ++i) {
        int a2 = ((LL)coef1 * (2 * i - 1) % Mod * a1 + (LL)coef2 * (i - 1) % Mod * a0) % Mod * Inv[i] % Mod;
        a0 = a1, a1 = a2;
        ans ^= a1;
    }
    printf("%d\n", ans);
}

int main() {
    Init(10000000);
    int Tests;
    scanf("%d", &Tests);
    while (Tests--) Solve();
    return 0;
}