#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>

int main(){
    int n, length_digit = 1; 
    scanf("%d",&n);
    int *r = malloc(60 * sizeof(int));
    r[0] = 1;
    for (int factor = 2; factor <= n; factor++) {
        int *carry = malloc( (length_digit + 2) * sizeof(int));
        // first, evaluate product
        for (int i = 0; i < length_digit; i++) {
            r[i] *= factor;
            r[i] += carry[i];
            if (r[i] / 100 > 0) {
                carry[i + 2] += r[i] / 100;
                carry[i + 1] += (r[i] % 100) / 10;
                r[i] = r[i] % 10;
            } else if (r[i] / 10 > 0) {
                carry[i + 1] += r[i] / 10;
                r[i] = r[i] % 10;
            }
        }
        
        // second, consider if length of digit increases
        if (carry[length_digit + 1] > 0) {
            r[length_digit + 1] = carry[length_digit + 1];
            r[length_digit + 1] += carry[length_digit] / 10;
            r[length_digit] = carry[length_digit] % 10;
            length_digit += 2;
        } else if (carry[length_digit] > 0) {
            r[length_digit] = carry[length_digit];
            length_digit++;
        }
    }
    
    // print
    for(int i = length_digit - 1; i >= 0; i--){
        printf("%d", r[i]);
    }
    
}