Can someone help me? With this source it is working for 2.031. How can I improve it?
#include<iostream>
using namespace std;
long long nod(long long a,int b){
 while(a!=0&&b!=0){
  if(a>b) a%=b;
  else b%=a;
 }
  return a+b;
 }
int main()

{
 long long  last[50000];
int n,k,i,j,l,br=0;
 cin>>n>>k;
 last[0]=1;
 for(i=0;i<=n;i++)
 {
  last[i]=1;
  for(j=i-1;j>0;j--)last[j]=last[j]+last[j-1];
 }
//cout<<last[k]<<endl;
 for(l=2;l<last[k];l++){
  if(nod(last[k],l)!=1) br++;
  while(last[k]%l==0)last[k]/=l;

 }
 cout<<br<<endl;
//system("pause");
 return 0;
}