https://www.acmicpc.net/submit/14681/62617860
if else 문 사용
import java.util.Scanner;
public class Main{
public static void main(String args[]){
Scanner sc = new Scanner(System.in);
int x = sc.nextInt();
int y = sc.nextInt();
if(x>0 && y>0)
System.out.println("1");
else if(x<0 && y>0)
System.out.println("2");
else if(x>0 && y<0)
System.out.println("4");
else if(x<0 && y<0)
System.out.println("3");
}
}