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.Collections;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using System.Text;
using System.Globalization;
using System.Diagnostics;
 
 
 
class Myon
{
    public Myon() { }
    public static int Main()
    {
        new Myon().calc();
        return 0;
    }
 
    Scanner cin;
 
    void calc()
    {
        cin = new Scanner();
        int A, B;
        A = cin.nextInt();
        B = cin.nextInt();
        int ans = A + B;
        if (ans >= 10) Console.WriteLine("error");
        else Console.WriteLine(ans);
        
    }
}
 
 
 
 
class Scanner
{
    string[] s;
    int i;
 
    char[] cs = new char[] { ' ' };
 
    public Scanner()
    {
        s = new string[0];
        i = 0;
    }
 
    public string next()
    {
        if (i < s.Length) return s[i++];
        string st = Console.ReadLine();
        while (st == "") st = Console.ReadLine();
 
        s = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
        i = 0;
        return s[i++];
    }
 
    public int nextInt()
    {
        return int.Parse(next());
    }
 
    public long nextLong()
    {
        return long.Parse(next());
    }
 
    public double nextDouble()
    {
        return double.Parse(next());
    }
 
}