#include<stdio.h>
int main()
{
    int n;
    long long factorial = 1;
    scanf("%d", &n);
    if (n < 0)
    {
        printf("Invalid input");
    }
    else
    {
        
        
        for (int i = 1; i<= n; i++) {
            factorial *=  i;
        }
        printf("%11d", factorial);
    }
        return 0; 
}