1 import java.util.Scanner; 2  3 public class Main { 4  5     public static void main(String[] args) { 6          7         Scanner sc=new Scanner(System.in); 8          9         while(true){10             11             int n=sc.nextInt();12             if(n==0) return ;13             int ans=sc.nextInt()+sc.nextInt();14             15             while(--n>0){16                 int t=sc.nextInt()+sc.nextInt();17                 ans=Math.max(t,ans);18             }19             20             System.out.println(ans);21         }22         23     }24     25 }