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)

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().trim().split_whitespace().map(|e|e.parse().unwrap())
	.collect::<Vec<String>>();
	let a = s[0].parse::<i32>().unwrap();
	let b = s[2].parse::<i32>().unwrap();
	if s[1] == "+" {
		println!("{}",a+b);
	}else{
		println!("{}",a-b);
	}
}