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.Linq;
using System.Collections.Generic;

class Program
{
    private static readonly Scanner sc = new Scanner();
    static void Main(string[] args)
    {
        int a = sc.Int;
        int b = sc.Int;

        Console.WriteLine(a + b < 10 ? (a + b).ToString() : "error");
    }
}

class Scanner
{
    private string[] _str = new string[0];
    private int _i;

    public string Line { get { return Console.ReadLine(); } }

    public string Str
    {
        get
        {
            if (_i >= _str.Length)
            {
                _str = Line.Split(' ');
                _i = 0;
            }
            return _str[_i++];
        }
    }

    public string[] StrArr { get { return Line.Split(' '); } }
    public int Int { get { return int.Parse(Str); } }
    public int[] IntArr { get { return Line.Split(' ').Select(int.Parse).ToArray(); } }
    public long Long { get { return long.Parse(Str); } }
    public long[] LongArr { get { return Line.Split(' ').Select(long.Parse).ToArray(); } }
    public double Double { get { return double.Parse(Str); } }
    public double[] DoubleArr { get { return Line.Split(' ').Select(double.Parse).ToArray(); } }
}