Задача на НОД

package com.javarush.task.task14.task1420; /* НОД */ import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; public class Solution { public static void main(String[] args) throws Exception { BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); int firstNumber = Integer.parseInt(reader.readLine()); int secondNumber = Integer.parseInt(reader.readLine()); if (firstNumber <= 0 || secondNumber <= 0) throw new NumberFormatException(); int nod = 0; int dividingNumber = 0; if (firstNumber > secondNumber) dividingNumber = firstNumber; else if (secondNumber > firstNumber) dividingNumber = secondNumber; else dividingNumber = firstNumber; for (int i = dividingNumber; i > 1; i--) { if ((firstNumber % i == 0) && (secondNumber % i == 0)) { nod = i; break; } } System.out.println(nod); } }