#include <bits/stdc++.h>
using namespace std;
const int mod = 998244353;
inline int qp(int a, int b) {
    int res = 1;
    while (b) {
        if (b & 1) res = 1ll * res * a % mod;
        a = 1ll * a * a % mod;
        b >>= 1;
    }
    return res;
}
const int N = 10000005;
int inv[N], f[N];
int main() {
    inv[1] = 1;
    for (int i = 2; i < N; i++) inv[i] = 1ll * (mod - mod / i) * inv[mod % i] % mod;
    int T;
    scanf("%d", &T);
    while (T--) {
        int n, c;
        scanf("%d%d", &n, &c);
        int cf1 = 2ll * (c + 1) % mod, cf2 = 4ll * c * c % mod;
        cf2 = (mod - cf2) % mod;
        f[1] = (2 + 2ll * c) % mod;
        f[2] = (4ll * c * c + 12ll * c + 6) % mod;
        for (int i = 3; i <= n; i++) {
            f[i] = (1ll * cf1 * (2 * i - 1) % mod * f[i - 1] + 1ll * cf2 * (i - 1) % mod * f[i - 2]) % mod * inv[i] % mod;
        }
        int ans = 0;
        for (int i = 1; i <= n; i++) ans ^= f[i];
        printf("%d\n", ans);
    }
    return 0;
}