#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<cmath>
#define ll long long
using namespace std;
const int MN=2e6+5;
const int mod=1e9+7;
ll n,m,d[MN],ans;
void write(ll n){if(n<0){putchar('-');write(-n);return;}if(n>9)write(n/10);putchar(n%10+'0');}
ll read(){ll x=0,f=1;char ch=getchar();while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}while(ch>='0'&&ch<='9'){x=(x<<1)+(x<<3)+(ch^48);ch=getchar();}return x*f;}
ll A(ll n, ll m){ll res=1;for(int i=n,j=1; j<=m; j++,i--)res=(res*i)%mod;return res;}
void solve(){
    n=read();m=read();ans=A(m,n);d[0]=1;d[1]=m-n;
    for(int i=2; i<=n; i++) d[i]=((m-n)*d[i-1]%mod+(i-1)*((d[i-1]+d[i-2])%mod)%mod)%mod;
    write(ans*d[n]%mod);putchar('\n');
}
int main(){
    ll T=read();while(T--)solve();
    return 0;
}