Не понимаю
package com.javarush.task.task14.task1420;
/*
НОД
*/
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
public class Solution {
public static void main(String[] args) throws IOException {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
String X = reader.readLine();
String Y = reader.readLine();
reader.close();
if (X.indexOf("-",0) == -1 || Y.indexOf("-",0) == -1) {
try {
int x = Integer.parseInt(X);
int y = Integer.parseInt(Y);
System.out.println(MostCommonЬultiple(x, y));
} catch (Exception e) {}
}
else {}
}
public static int MostCommonЬultiple(int x, int y){
List<Integer> arrayX = del(x);
List<Integer> arrayY = del(y);
List<Integer> XandY = CompareArray(arrayX,arrayY);
return MaxOfCom(XandY);
}
public static List<Integer> del(int a){
List<Integer> divider = new ArrayList<>();
for (int i = 0; i <= a; i++) {
if (a % i == 0) {
divider.add(i);
}
}
return divider;
}
public static List<Integer> CompareArray(List<Integer> a, List<Integer> b){
List<Integer> compare = new ArrayList<>();
for (int i = 0; i < a.size(); i++){
for (int j = 0; j < b.size(); j++){
if (a.get(i).equals(b.get(j))) compare.add(a.get(i));
}
}
return compare;
}
public static int MaxOfCom(List<Integer> a){
int max = a.get(0);
for (int i = 0; i<a.size();i++){
if(max<a.get(i)) max = a.get(i);
}
return max;
}
}