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: Wrong Answer)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;


class Program
{
    static void Main(string[] args)
    {
        string S = Console.ReadLine();
        string answer = null;
        for (int i = 0; i < S.Length; i++)
        {
            for (int g = 0; g < S.Length; g++)
            {
                if (i == g) break;
                if (S[i] == S[g]) { answer = "no"; }
            }
        }
        if (answer == null) answer = "yes";
        Console.WriteLine(answer);
    }
}