import java.util.Scanner;
public class Yuki208{
	public static void main(String[] arg){
		Scanner sc = new Scanner(System.in);
		int x,y,x1,y1;
		x = sc.nextInt();
		y = sc.nextInt();
		x1 = sc.nextInt();
		y1 = sc.nextInt();
		if(x == y && x1 == y1 && x1 <x){
			System.out.println(x+1);
		}else{
			if(x> y){
				System.out.println(x);
			}else{
				System.out.println(y);
			}
		}
	}
}