Uva 10219- Find The ways!

/*                                                     CODEMAN

ARIF KHAN NIHAR

Uva 10219- Find The ways!

date -> 10/20/2016

*/

#include<bits/stdc++.h>

using namespace std;

#define logdiv(n) log(n)/log(10)

int main()

{

double re;

long n,k;

while(cin>>n>>k) {

re = 0;

for( int i = 0 ; i < k ; i++ ) {

re += logdiv(n-i) - logdiv(i+1) ;

}

cout << floor(re)+1 << endl;

}

return 0;

     }