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