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 Go (1.6) (judge verdict: Accepted)

package main

import "fmt"

func main() {
	var a, b int
	fmt.Scan(&a, &b)
	if a + b < 10 {
		fmt.Println(a + b)
	} else {
		fmt.Println("error")
	}
}