#include <iostream>
using namespace std;
int main(){
	int n;
	long long last=1;
	cin>>n;
	for(int i=n;i>=2;i--){
		last*=i;
	}
	cout<<last<<endl;
}

### Prompt

Please provide a Cpp coded solution to the problem described below:

Write a program which reads an integer n and prints the factorial of n. You can assume that n ≤ 20.



Input

An integer n (1 ≤ n ≤ 20) in a line.

Output

Print the factorial of n in a line.

Example

Input

5


Output

120

### Response

```cpp
#include <iostream>
using namespace std;
int main(){
	int n;
	long long last=1;
	cin>>n;
	for(int i=n;i>=2;i--){
		last*=i;
	}
	cout<<last<<endl;
}

```