Problem:
Score : 100 points

Problem Statement

You are given two integers A and B as the input. Output the value of A + B.

However, if A + B is 10 or greater, output error instead.

Constraints

A and B are integers.

1 ≤ A, B ≤ 9

Input

Input is given from Standard Input in the following format:

A B

Output

If A + B is 10 or greater, print the string error (case-sensitive); otherwise, print the value of A + B.

Sample Input 1

6 3

Sample Output 1

9

Sample Input 2

6 4

Sample Output 2

error

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Text;
using System.Text.RegularExpressions;
using System.Diagnostics;
using System.Linq;
using System.Collections.Generic;

namespace competitive
{
    class Program
    {
        static void Main(string[] args)
        {
            var ab = Console.ReadLine()
            .Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries)
            .Select(x => int.Parse(x))
            .Sum();
            if (ab >= 10)
            {
                Console.WriteLine("error");
            }
            else
            {
                Console.WriteLine(ab);
            }
        }
    }
}