C++ :

#include <bits/stdc++.h>
using namespace std;

int main(){
    int a,b,c,d;
    cin>>a;
    b = a / 10 % 10;
	c = a % 10;
	d = c * 10 + b;
	cout<<d<<endl; 
}

Java :

import java.util.Scanner;
public class Main
{   
	public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        int a = x/10;
        int b = x%10;
        System.out.println(b*10+a);
    
    }
}