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 Rust (1.15.1) (judge verdict: Accepted)

use std::io;

fn read_line()-> String {
    let mut s = String::new();
    let _ = io::stdin().read_line(&mut s).unwrap();
    s
}

fn main() {
	let s = read_line().split_whitespace().map(|e|e.parse().unwrap())
	.collect::<Vec<i32>>();
	let r = s[0] + s[1];
	if  r < 10 {
		println!("{}",r);
	}else{
		println!("error");
	}
}