#include<stdio.h>

int main(void){
  unsigned long long num=1,input,i;
  scanf("%llu",&input);
  for(i=2;i<=input;i++){
    num*=i;
    num%=1000000000000;
    if(num==0) break;
  }
  printf("%llu\n",num);
  return 0;
}