#include <stdio.h>

int fact(int n) 
{ 
    int res = 1; 
    for (int i = 2; i <= n; i++) 
        res = res * i; 
    return res; 
} 


int nCr(int n, int r) 
{ 
    return fact(n) / (fact(r) * fact(n - r)); 
} 
  
int main() 
{ 
    int n,r; 
    printf("Enter the value of n:-\n"); 
    scanf("%d",&n);
    printf("Enter the value of r:-\n");
    scanf("%d",&r);
    
    printf("%d\n",nCr(n,r));
    return 0; 
}