import java.io.*; public class Solution { public static void main(String[] args) throws Exception { //write your code here BufferedReader bf=new BufferedReader(new InputStreamReader(System.in)); int a=Integer.parseInt(bf.readLine()); int b=Integer.parseInt(bf.readLine()); int c=Integer.parseInt(bf.readLine()); int d=Integer.parseInt(bf.readLine()); if (a>=b&&b>=c&&c>=d){ System.out.println(a); } else if (b>=a&&b>=c&&c>=d){ System.out.println(b); } else if(c>=a&&c>=b&&c>=d) { System.out.println(c); } else { System.out.println(d); } } }