#include <cstdio>
using namespace std;
const int mod = 1e9 + 7;
long long inv[4000010], invfac[4000010], fac[4000010];
int t, n, m;
long long dp[2000010];
long long pow_mod(long long n, long long p, long long mod) {
    long long res = 1;
    for (; p; p >>= 1, n = n * n % mod) {
        if (p & 1) {
            res = res * n % mod;
        }
    }
    return res;
}
long long A(long long n, long long m) {
    return fac[n] * invfac[n - m] % mod;
}
long long C(long long n, long long m) {
    return fac[n] * invfac[m] % mod * invfac[n - m] % mod;
}
int main() {
    invfac[0] = invfac[1] = inv[1] = fac[0] = fac[1] = 1;
    for (int i = 2; i <= 4000000; i++) {
        inv[i] = (mod - mod / i) * inv[mod % i] % mod;
        invfac[i] = invfac[i - 1] * inv[i] % mod;
        fac[i] = fac[i - 1] * i % mod;
    }
    scanf("%d", &t);
    while (t--) {
        scanf("%d%d", &n, &m);
        for (int i = 0; i <= n; i++) {
            dp[i] = A(m, n) * A(m - i, n - i) % mod;
        }
        long long ans = 0;
        for (int i = 0; i <= n; i++) {
            if (i % 2 == 0) {
                ans += dp[i] * C(n, i) % mod;
            } else {
                ans -= dp[i] * C(n, i) % mod;
            }
        }
        ans = (ans % mod + mod) % mod;
        printf("%lld\n", ans);
    }
    return 0;
}