C :

#include<stdio.h>
int main()
{
	int a,b,c;
	scanf("%d%d",&a,&b);
	c=a,a=b,b=c;
	printf("%d %d\n",a,b);
	return 0;
}

C++ :

#include<stdio.h>
int main()
{
    int a,b,c;
    scanf("%d %d",&a,&b);
    c=a;
    a=b;
    b=c;
    printf("%d %d",a,b);
    return 0;
}

Java :

import java.util.Scanner;
public class Main {
    public static void main(String[] args){
        Scanner input=new Scanner(System.in);
        int n=input.nextInt();
        int m=input.nextInt();
        int t=n;
        n=m;
        m=t;
        System.out.println(n+" "+m);
    }
}

Python :

# coding=utf-8
#python2
a,b=map(int,raw_input().split())
c=a
a=b
b=c
print a,b

C# :

using System;
using System.Collections.Generic;
using System.Diagnostics.SymbolStore;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp2
{
    internal class Program
    {
        static void Main()
        {
            //int[] days = { 31,28,31,30,31,30,31,31,30,31,30,31};
            string[] a1 = Console.ReadLine().Split();
            string a = a1[1];
            string b = a1[0];


            Console.WriteLine(a+" "+b);

            Console.ReadKey();



        }
    }
}