C :

#include<stdio.h>
int main()
{
	int n;
	scanf("%d",&n);
	printf("%d%d%d\n", n%10, (n/10)%10, n/100);
	return 0;
 } 

C++ :

#include <stdio.h>
#include <math.h>
int main()
{
    int a,b,c,d;
    scanf("%d",&a);
    b=(a-a%100)/100;
    c=(a-100*b)-(a-100*b)%10;
    c=c/10;
    d=a-100*b-10*c;
    printf("%d%d%d",d,c,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 x=0;
        while(n>0){
            System.out.print(n%10);
            n/=10;
            x++;
        }
        if(x<3) System.out.print(0);
        if(x<2) System.out.print(0);
        if(x<1) System.out.print(0);
    }
}

Python :

# coding=utf-8
#!/usr/bin/python2
import sys
num=raw_input()
num=int(num)
a=num%10
b=num/10%10
c=num/100%10
sys.stdout.write(str(a))
sys.stdout.write(str(b))
sys.stdout.write(str(c))

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();
            string b1 =Convert.ToString( a1[2]) + Convert.ToString( a1[1]) +Convert.ToString( a1[0]);

            Console.WriteLine(b1);
            Console.ReadKey();



        }
    }
}