#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX 431

int n,k;
int divis[MAX+5];

int primes[MAX+1];
int primes_len;

void f(int num,int delta) {
  int i=0;
  while (num>1) {
    while ((num%primes[i]) == 0) {
      divis[primes[i]]+=delta;
      num/=primes[i];
    }

    i++;
  }
}

int main(void) {

  primes[0]=2;
  primes_len=1;

  int p=3;
  while (p<=MAX) {
    int i;
    for (i=0;i<primes_len;i++)
      if ((p % primes[i]) == 0) break;
    if (i>=primes_len) primes[primes_len++]=p;
    p+=2;
  }

  while (n=-1, scanf("%d %d",&n, &k), n!=-1) {
    memset(divis,0,sizeof(divis));

    if (k>n/2) k=n-k;
    for (int i=n;i>=n-k+1;i--) f(i,1);
    for (int i=1;i<=k;i++) f(i,-1);

    unsigned long long sum=1;
    for (int i=0;i<primes_len;i++) sum*=divis[primes[i]]+1;

    printf("%llu\n",sum);
  }

  return 0;
}