import java.util.*;

public class Main {
    static final long MOD = 1000000000000L;
	public static void main (String[] args) {
    	Scanner sc = new Scanner(System.in);
    	long n = sc.nextLong();
    	long ans = 1;
    	boolean isMod = false;
    	for (int i = 0; i < n && ans > 0; i++) {
    	    ans *= i + 1;
    	    if (!isMod && ans >= MOD) {
    	        isMod = true;
    	    }
    	    if (isMod) {
    	        ans %= MOD;
    	    }
    	}
    	if (isMod) {
    	    System.out.printf("%012d\n", ans);
    	} else {
    	    System.out.println(ans);
    	}
	}
}