why the last one is not valided ?
package fr.codegym.task.task04.task0425;
/*
Cible verrouillée !
*/
import java.io.*;
import java.util.Scanner;
public class Solution {
public static void main(String[] args) throws Exception {
Scanner input = new Scanner(System.in);
int a = input.nextInt();
int b = input.nextInt();
if ((a>0)&&(b>0))
System.out.println("1");
else if ((a<0)&&(b>0))
System.out.println("2");
else if ((a<0)&&(b<0))
System.out.println("3");
else if ((a<0)&&(b<0))
System.out.println("4");
}
}