UVA 530 - Binomial Showdown

/***
Md. Nazmul Hasan
Shahjalal University of Science & Technology,Sylhet.
hasan08sust@gmail.com
***/
#include<iostream>
#include<cstdio>
#include<stack>
#include<queue>
#include<map>
#include<vector>
#include<algorithm>
#include<cstring>
#include<sstream>
#include<cmath>
#include <iomanip>
using namespace std ;
typedef long long ll ;
typedef int in ;
typedef unsigned long long ull ;
const double pi = 2*acos(0) ;
#define maxi 40000
#define pf printf
#define sc scanf
#define pb push_back
#define MEM(x,y) (memset((x),(y),sizeof(x)))
#define MIN(x,y) ((x) < (y) ? (x) : (y))
#define MAX(x,y) ((x) > (y) ? (x) : (y))
#define load(array,size)  for(int i=0 ; i<size ; i++) cin>>array[i]  ;
#define new_line  pf("\n")
#define clear_data(array) memset(array,0,sizeof(array))
#define highest_int 2147483647


int main()
{

    ll n,m,res,i,num,p ;
    while(sc("%lld %lld",&n,&m)==2)
    {
        if(n==0 && m==0)
            break;
        res = 1 ;
        if(n-m < m)
            p = n-m;
        else
            p = m;
        num = n;
        for(i=1 ; i<=p ; i++,num--)
        {
            res = res * num;
            res = res/i;
        }

        pf("%lld\n",res);
    }
    return 0;
}