[백준] 2558번 : A+B-2- Dart(다트)

https://www.acmicpc.net/problem/2558

import 'dart:io';
void main(){
    String? s=stdin.readLineSync();
    var a=int.parse(s!);
    s=stdin.readLineSync();
    var b=int.parse(s!);
    print(a+b);
}