#include <iostream.h>
#include <conio.h>
double factorial(int a)
{
double f = 1;
while (a > 1)
{
f *= a;
a--;
}
return f;
}
int main()
{
int n, r;
double result;
cout << "Please enter number n :";
cin >> n;
cout << "Please enter number r :";
cin >> r;
result = factorial(n) / (factorial(r) * factorial(n - r));
cout << "Result = " << result << endl;
getch();
return 0;
}