Problem:
Score : 100 points

Problem Statement

Joisino wants to evaluate the formula "A op B".
Here, A and B are integers, and the binary operator op is either + or -.
Your task is to evaluate the formula instead of her.

Constraints

1≦A,B≦10^9

op is either + or -.

Input

The input is given from Standard Input in the following format:

A op B

Output

Evaluate the formula and print the result.

Sample Input 1

1 + 2

Sample Output 1

3

Since 1 + 2 = 3, the output should be 3.

Sample Input 2

5 - 7

Sample Output 2

-2

Solution in Rust (1.15.1) (judge verdict: Accepted)

fn read() -> Vec<String> {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    let vec:Vec<String> = s.trim().split_whitespace().map(|x| x.to_string()).collect();
    vec
}

fn main(){
    let vec:Vec<String> = read();
    let s = vec[1].as_str();
    let a:i32 = vec[0].parse().unwrap();
    let b:i32 = vec[2].parse().unwrap();
    match s {
        "+" => println!("{}", a + b),
        _ => println!("{}", a - b),
    };
}