#include<stdio.h>
int m[10000],mh=0,c=0,n,i;
int main(){
    m[0] = 1;
    scanf("%d",&n);
    while(n>1){
        i=0;
        while(c!=0 || i<=mh){
            m[i] =m[i]*n+c;
            c = m[i]/10;
            m[i] %= 10;
            if(i>mh) mh = i;
            i++;
        }
        n--;
    }
    for(;mh>=0;mh--) printf("%d",m[mh]);
    return 0;
}