Background

If you're new to programming contests, please read this carefully:

In programming contests, your program's output must contain only the answer—nothing extra.

That includes messages like "Please enter integers a and b" or any other prompts for the user.

If you print anything like that, the system will mark your submission as Wrong Answer (shown as WA on Luogu).

When checking your output, the judge system will ignore spaces at the end of any line and extra blank lines after the last line of output.

But if your code prints extra text (like prompts or explanations), it will be marked wrong—even if the answer itself is correct.

So, if your program works fine on your own computer but gets WA when you submit it, don't blame the judge system.

Instead, double-check that you're not printing anything unnecessary. You can look at the sample code at the end of this problem for reference.

Also, try using the IDE mode on Luogu—it helps avoid small differences between your local environment and the judge's system.

Finally, don't post your solution in the discussion section.

Solutions should go in the "Solution" area. If you post a full solution in the discussion section, it may be deleted, and you could even be muted.

If you can't submit a solution, it means too many people have already done so—but you still shouldn't post it in the discussion section.

Only if your method is truly different from all existing ones should you contact a site admin to ask for permission to add your solution.

Problem Description

Input two integers, $a$ and $b$, and output their sum ($|a|,|b| \le {10}^9$).

Notes:

1. In Pascal, using integer may overflow.
2. Negative numbers are allowed.
3. In C/C++, the main function must return int, and you must return 0. This is a general requirement for problems on Luogu as well as in NOIP/CSP/NOI contests.

Let's get started with this simple problem and begin the journey toward becoming an expert.

Every great idea has a humble beginning.

Input Format

Two space-separated integers.

Output Format

A single integer.

20 30

50

Hint

Program Examples in Various Languages:

C

#include <stdio.h>

int main()
{
    int a,b;
    scanf("%d%d",&a,&b);
    printf("%d\n", a+b);
    return 0;
}

C++

#include <iostream>
#include <cstdio>

using namespace std;

int main()
{
    int a,b;
    cin >> a >> b;
    cout << a+b << endl;
    return 0;
}

Pascal

var a, b: longint;
begin
    readln(a,b);
    writeln(a+b);
end.

Python3

s = input().split()
print(int(s[0]) + int(s[1]))

Java

import java.io.*;
import java.util.*;
public class Main {
    public static void main(String args[]) throws Exception {
        Scanner cin=new Scanner(System.in);
        int a = cin.nextInt(), b = cin.nextInt();
        System.out.println(a+b);
    }
}

JavaScript (Node.js)

const fs = require('fs')
const data = fs.readFileSync('/dev/stdin')
const result = data.toString('ascii').trim().split(' ').map(x => parseInt(x)).reduce((a, b) => a + b, 0)
console.log(result)
process.exit() // Ensure this line is added at the exit point

Ruby

a, b = gets.split.map(&:to_i)
print a+b

PHP

<?php
$input = trim(file_get_contents("php://stdin"));
list($a, $b) = explode(' ', $input);
echo $a + $b;

Rust

use std::io;

fn main(){
    let mut input=String::new();
    io::stdin().read_line(&mut input).unwrap();
    let mut s=input.trim().split(' ');

    let a:i32=s.next().unwrap()
               .parse().unwrap();
    let b:i32=s.next().unwrap()
               .parse().unwrap();
    println!("{}",a+b);
}

Go

package main

import "fmt"

func main() {
    var a, b int
    fmt.Scanf("%d%d", &a, &b)
    fmt.Println(a+b)
}

C# Mono

using System;

public class APlusB{
    private static void Main(){
        string[] input = Console.ReadLine().Split(' ');
        Console.WriteLine(int.Parse(input[0]) + int.Parse(input[1]));
    }
}

Visual Basic Mono

Imports System

Module APlusB
    Sub Main()
        Dim ins As String() = Console.ReadLine().Split(New Char(){" "c})
        Console.WriteLine(Int(ins(0))+Int(ins(1)))
    End Sub
End Module

Kotlin

fun main(args: Array<String>) {
    val (a, b) = readLine()!!.split(' ').map(String::toInt)
    println(a + b)
}

Haskell

main = do
    [a, b] <- (map read . words) `fmap` getLine
    print (a+b)

Lua

a = io.read('*n')
b = io.read('*n')
print(a + b)

OCaml

Scanf.scanf "%i %i\n" (fun a b -> print_int (a + b))

Julia

nums = map(x -> parse(Int, x), split(readline(), " "))
println(nums[1] + nums[2])

Scala

object Main {
  def main(args: Array[String]): Unit = {
    import java.util.Scanner
    
    val cin = new Scanner(System.in)
    val a = cin.nextInt()
    val b = cin.nextInt()
    System.out.println(a + b)
  }
}

Perl

my $in = <STDIN>;
chomp $in;
$in = [split /[\s,]+/, $in];
my $c = $in->[0] + $in->[1];
print "$c\n";