import java.util.*;
public class Main{
    public static void main (String [] args) {
        Scanner scn = new Scanner (System.in);
        
        int n = scn.nextInt();
        if (n<0 || n>10) {
            System.out.print("Invalid input");
            return;
        }
        
        int arr[] = new int [n];
        for (int i=0; i<n; i++) {
            if (scn.hasNestInt()) {
                System.out.print("Invalid input");
                return;
            }
            arr[i]=scn.nextInt();
        }
        
        int max = 0;
        for (int i=0; i<n; i++) {
            max= Math.max(max,arr[i]);
        }
        System.out.print(max);
    }
}