#include <iostream>
using namespace std;
unsigned long long int npok( unsigned int n, unsigned int k )
{
if( k == 0 || k == n ) return 1;
if( n > 0 && k > 0 && n > k ) return npok( n - 1, k ) + npok( n - 1, k - 1 );
}
int main ()
{
int ile;
cin>>ile;
for (int i=0; i<ile; i++)
{
unsigned long long int a,b;
cin>>a>>b;
cout<<npok(a,b)<<endl;
}
return 0;
}
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