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;

class Atcoder51
{
    public static void Main()
    {
        string[] input = Console.ReadLine().Split(' ');
        int a = int.Parse(input[0]);
        int b = int.Parse(input[1]);

        if (a + b >= 10)
            Console.WriteLine("error");
        else
            Console.WriteLine(a + b);
    }
}