import java.io.*;
import java.util.*;

class Main {
	
	public static void out (Object o) {
		System.out.println(o);
	}
		
	public static void main (String[] args) throws IOException {
		BufferedReader br = 
			new BufferedReader(new InputStreamReader(System.in));
		
		String[] line1 = br.readLine().split(" ");
		String[] line2 = br.readLine().split(" ");
		
		int x = Integer.parseInt(line1[0]);
		int y = Integer.parseInt(line1[1]);
		int x2 = Integer.parseInt(line2[0]);
		int y2 = Integer.parseInt(line2[1]);
		int ans = Math.max(x , y);
		
		out(x == y && x2 == y2 && x2 < x ? ans + 1 : ans);
	}
}