// recurs.cpp: Recursion
#include <iostream>
using namespace std;

float f(float n) {
 float x = n-1, y;
  if (n <= 1)
   y = 1;
  else
   y = n * f(x);
 return y;
}

int main() {
 float number; 
 cout << "Enter n to determine n!: ";
 cin >> number;
 cout << " Your sum is: " << f(number) << endl;
}