#include<stdio.h>
main()
{
    __int64 n, m, i, s, t;
    while ( scanf ( "%I64d", &t ) != EOF )
    {
        while ( t-- )
        {
            scanf ( "%I64d%I64d", &n, &m );
            s = 1;
            if ( n < m )
                s = 0;
            else if ( m == 0 ) s = 1;
            else
            {
                if ( m > n / 2 )
                    m = n - m;
                for ( i = 1; i <= m; i++ )
                {
                    s *= ( n - i + 1 );
                    s /= i;
                }
            }
            printf ( "%I64d\n", s );
        }
    }
}