#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll mod = 1e9+7;
const int MAXN = 2e6+10;
ll fac[MAXN],rev[MAXN];
ll ksm(ll a,ll b){
    ll re=1;
    while(b){
        if(b&1)re=re*a%mod;
        a=a*a%mod;
        b>>=1;
    }return re;
}
ll f[MAXN];
void Init(){
    fac[0]=1;
    for(int i=1;i<MAXN;++i)fac[i]=fac[i-1]*i%mod;
    rev[MAXN-1]=ksm(fac[MAXN-1],mod-2);
    for(int i=MAXN-2;~i;--i)rev[i]=rev[i+1]*(i+1)%mod;
}
ll C(int n,int m){if(m>n)return 0;return fac[n]*rev[m]%mod*rev[n-m]%mod;}
int main(){
    Init();
    int T;scanf("%d",&T);
    while(T--){memset(f,0,sizeof(f));
        int n,m;scanf("%d%d",&n,&m);
        for(int i=0;i<=n;++i)f[i]=C(n,i)*C(m,i)%mod*C(m-i,n-i)%mod*C(m-i,n-i)%mod*fac[n-i]%mod*fac[n-i]%mod*fac[i]%mod;
        ll ans=0;
        for(int i=0;i<=n;++i)ans=(ans+f[i]*((i&1)?mod-1:1)%mod)%mod;
        printf("%lld\n",ans);
    }
    return 0;
}