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 Lua (5.3.2) (judge verdict: Accepted)

#!/usr/bin/env lua

s = io.read("*line")
nlist = {}
j = 1
for i in string.gmatch(s, "%S+") do
    nlist[j] = tonumber(i)
    j = j + 1
end

if nlist[1] + nlist[2] >= 10 then
    print("error")
else
    print(nlist[1]+nlist[2])
end