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 gets() -> String {
    let mut buf = String::new();
    io::stdin().read_line(&mut buf).ok();
    buf
}

fn main() {
    let line = gets();
    let mut it = line
        .trim()
        .split_whitespace()
        .map(|x| x.parse::<i32>().unwrap());
    let a = it.next().unwrap();
    let b = it.next().unwrap();
    if a + b < 10 {
        println!("{}", a + b);
    } else {
        println!("error");
    }
}