#include<stdio.h>
#include<string.h>
#define maxn 3000
int  f[maxn];
int main()
{
    int n,i,j;
    scanf("%d",&n);
    memset(f, 0, sizeof(f));
    f[0] = 1;
    for( i = 2;i <= n; i++)
    {
        int c=0;
        for( j = 0; j < 3000; j++)
        {
            int s = f[j] * i + c;
            f[j] = s % 10;
            c = s / 10;
        }

    }
    for(j = maxn-1;j >= 0; j--)
        if(f[j])break;
    for(i = j; i >= 0 ;i--)
        printf("%d",f[i]);
    return 0;

}