Go: package main

import (
	"bufio"
	"os"
	"fmt"
)

func reverse(s string) string {
	runes := []rune(s)
	for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
		runes[i], runes[j] = runes[j], runes[i]
	}
	return string(runes)
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Scan()
	input := scanner.Text()
	fmt.Println(reverse(input))
}

C++: #include <cstdio>
#include <iostream>
#include <algorithm>
using namespace std;
 
int main() {
    char a[25], i;
    scanf("%s", &a);
    for(i=strlen(a)-1;i>=0;i--){
       printf("%c", a[i]);                         
                             
    }
    printf("\n");
    
    return 0;
}

C++: #include <iostream>

using namespace std;

int main(){
        char s[21];
        cin >> s;
        int n = 0;
        while(*(s+n)){
                n++;
        }   
        for(;n > 0;n--){
                cout << *(s+n-1);
        }   
        cout << endl;
}

C++: #include<iostream>
#include<string>
#include<algorithm>
#include <stdio.h>
using namespace std;


 int main(){
    string a;
    cin >> a;
    int len=a.length();
    for(int i=len;i>=0 ; i--)
    cout << a[i];
    cout<<endl;
 }

C++: #include <iostream>
#include <cstdio>
#include <string.h>

using namespace std;
static const int MAXV = 21;

int main() {
  char A[MAXV]={};
  cin >> A;
  int i=0;
  for(;i<MAXV;i++) {
    //printf("%c", A[i]);
    if (A[i] == 0) break;
  }
  i--;
  for(;i!=0;i--) {
    printf("%c", A[i]);
  }
  printf("\n");
}

C++: #include <iostream>
#include <cstring>
using namespace std;
int main(){
	char str[21];//="Hello world!";
	cin>>str;
	for(int i=strlen(str)-1;i>=0;--i){
		cout<<str[i];
	}
	return 0;
}

C++: #include <cstdio>
#include <cstring>
 
int main(){
 char str[21];
 scanf("%s",str);
 for(int i = strlen(str) - 1;i >= 0;i--){printf("%c",str[i]);}
 printf("\n");
 return 0;
}

C++: #include<iostream>
#include<string>
using namespace std;

int main()
{
	string str;
	cin >> str;

	for(int i=str.size()-1;i>=0;--i){
		cout << str[i];
	}

	return 0;
}

C++: #include <stdio.h>
#include <string.h>
 
int main(void)
{
  char str[25] = {0};
  int cx;

  fgets(str, sizeof(str), stdin);
  cx = strlen(str);

  for (int x=cx-2; x>=0; x--) {
    putchar(str[x]);
  }
  putchar(str[cx -1]);
 
  return 0;
}

C++: #include <iostream>

using namespace std;

int main() {
    int i,len;
    string ch;

    cin >> ch;

    len = ch.length();

    for(i = 0;i < len / 2;i++){
        char box = ch[i];
        ch[i] = ch[len - i];
        ch[len - i] = box;
    }

    for(i = 0; i <= len;i++){
        cout << ch[i];
    }
    cout << endl;

    return 0;
}

C++: // clang-format off
#include <bits/stdc++.h>
#define int long long
#define main signed main()
// #define main int main()
#define loop(i, a, n) for (int i = (a); i < (n); i++)
#define rep(i, n) loop(i, 0, n)
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define prec(n) fixed << setprecision(n)
#define stlice(from, to) substr(from, (to) - (from) + 1)
#define pb push_back
#define mp make_pair
#define mt make_tuple
#define fi first
#define se second
using namespace std;
using pii = pair<int, int>;
using vi = vector<int>;
using vd = vector<double>;
using vc = vector<char>;
using vb = vector<bool>;
using vs = vector<string>;
using vpii = vector<pii>;
using vvi = vector<vi>;
using vvb = vector<vb>;
using vvpii = vector<vpii>;
template<typename A> using fn = function<A>;
constexpr int INF = sizeof(int) == sizeof(long long) ? 1000000000000000000LL : 1000000000;
constexpr int MOD = 1000000007;
constexpr double PI = acos(-1);
template<typename A, typename B> bool cmin(A &a, const B &b) { return a > b ? (a = b, true) : false; }
template<typename A, typename B> bool cmax(A &a, const B &b) { return a < b ? (a = b, true) : false; }
constexpr bool odd(const int &n) { return n & 1; }
constexpr bool even(const int &n) { return !odd(n); }
template<typename V> constexpr typename V::value_type sum(const V &v) { return accumulate(all(v), 0); }
void solve();
main { solve(); return 0; }
// clang-format on

void solve() {
  string s;
  cin >> s;
  reverse(all(s));
  cout << s << endl;
}

C++: using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace coding
{
    class Program
    {
        static void Main(string[] args)
        {
            string input = Console.ReadLine();
            string output = "";             
            for (int i = input.Length - 1; i >= 0; i--)
            {
                output = output + input[i];
            }
            Console.WriteLine(output);
        }
    }
}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <string>
#include <cctype>

using namespace std;

int main() {

	string st;
	int stlen;

	while (cin >> st) {
		stlen = st.size();
		for (int i = stlen - 1; i >= 0; i--) {
			cout << st[i];
		}
		putchar('\n');
	}
	
	return 0;
}

C++: #include<iostream>
#include<string>
using namespace std;
int main(){
	string a;
		cin >> a;
		if(a.length() > 20){
			return 0;
		}

	for(int i=a.length()-1; i>-1; i--){
		cout << a[i];
		}
	return 0;
}

C++: #include<iostream>
#include<string>
#include<algorithm>

using namespace std;

int main(void){
  string moji;
  while(cin >> moji){
    reverse(moji.begin(),moji.end());
    cout << moji << endl;
  }
  return 0;
}

C++: #include<stdio.h>

int main(void)
{
	int i = 0 ;
	char str[100];
	
	scanf("%s",str);
	
	for(;str[i] != NULL ; i++);
	for(; i >= 0 ; i--) printf("%c",str[i]);
}

C++: #include<iostream>
#include<string>
#include<iomanip>
using namespace std;
int main(){
	string a;
	cin>>a;
	for(int i=0;i<a.size();i++){
		cout<<a[a.size()-i-1];
	}
	cout<<endl;
	return 0;
}

C++: #include <iostream>
#include <string>
#include <algorithm>

using namespace std;

int main(void){
	string s;
	while(cin >> s){
		reverse(s.begin(),s.end());
		cout << s << "\n";
	}
	return 0;
}

C++: #include <string>
#include <iostream>

int main(){
    std::string str;
    std::cin >> str;

    for (int i=str.length();i>=0;--i)
    {
        std::cout << str[i];
    }
    std::cout << std::endl;
}

C++: #include<stdio.h>
int main(){
    char str[21]={0};
    int cou=0;
    scanf("%s",str);
    for(int i=0;str[i]!='\0';i++){
        cou++;
    }
    for(int i=cou-1;i>=0;i--){
        printf("%c",str[i]);
    }
    return 0;
}

C++: #include <stdio.h>
#include <string>
#include <string.h>
#include <cstring>
#include <algorithm>

using namespace std;
int a;
char test[21];
char temp;

int main()
{
	scanf("%s",test);
	for(a=strlen(test)-1;a>=0;a--)
	{
	printf("%c",test[a]);
	}
	printf("\n");
	return 0; 
}