import java.util.Scanner;

class Main{
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		int x=sc.nextInt(),y=sc.nextInt(),x2=sc.nextInt(),y2=sc.nextInt();
		sc.close();
		if(x==y&&x2==y2&&x>x2) System.out.print(x+1);
		else if(x>y) System.out.print(x);
		else System.out.print(y);
	}
}