public class P1009 {

	public static void main(String[] args) {
		// TODO 自动生成的方法存根
		Scanner sc = new Scanner(System.in);
		int number = sc.nextInt();
		String result = "1";
		for(int m = 2 ; m <= number; m++) {
			String num1 = Integer.toString(m);
			result = multiply(result,num1);
			
		}
		
		System.out.print(result);
	
		
		
	}	
	public static String multiply(String num1, String num2) {
        int len1 = num1.length();
        int len2 = num2.length();
        int[] result = new int[len1 + len2];

        for (int i = len1 - 1; i >= 0; i--) {
            int digit1 = num1.charAt(i) - '0';

            for (int j = len2 - 1; j >= 0; j--) {
                int digit2 = num2.charAt(j) - '0';

                int product = digit1 * digit2;

                int pos1 = i + j;
                int pos2 = i + j + 1;

                int sum = product + result[pos2];

                result[pos1] += sum / 10;
                result[pos2] = sum % 10;
            }
        }

        StringBuilder sb = new StringBuilder();
        for (int digit : result) {
            if (!(sb.length() == 0 && digit == 0)) {
                sb.append(digit);
            }
        }

        return sb.length() == 0 ? "0" : sb.toString();
	}}