package com.javarush.task.task15.task1531; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.math.BigDecimal; /* Факториал */ public class Solution { public static void main(String[] args) throws IOException { BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); int input = Integer.parseInt(reader.readLine()); reader.close(); if (input <= 150) { System.out.println(factorial(input)); } } public static String factorial(int n) { if (n < 0) { System.out.println("0"); } else if (n == 0) { System.out.println("1"); } else { if (n == 1) { return String.valueOf((BigDecimal.valueOf(1))); } else { BigDecimal result = BigDecimal.ONE; for (int i = 1; i <= n; i++) { result = result.multiply(BigDecimal.valueOf(i)); } System.out.println(result.toString()); } } return ""; } }