#include<iostream>
using namespace std;
int fact(int n)
{
if(n==1)
return 1;
return n*fact(n-1);
}
int main()
{
int Testnum, N, M;
cin>>Testnum;
for(int i=0; i<Testnum; i++)
{
cin>>N>>M;
cout<<fact(M)/fact(N)*fact(M-N)<<endl;
//cout<<fact(M)<<endl;
}
return 0;
}
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