import java.util.Scanner;

public class EqualPairs {
    public static void main(String[] args) {
        Scanner scanner=new Scanner(System.in);

        int n=Integer.parseInt(scanner.nextLine());
        int lastSum=0;
        int maxDiff=0;

        for (int i=0;i<n;i++){
            int numberOne=Integer.parseInt(scanner.nextLine());
            int numberTwo =Integer.parseInt(scanner.nextLine());
            int currentSum=numberOne+numberTwo;