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<stdio.h>
#include<string.h>

int main(){
	char str[21],reverse[21];
	int num,i;
	num=scanf("%21s",str);
	
	
	num=strlen(str)-1;
	
	for(i=0;i<=num;i++){
		reverse[i]=str[num-i];
	}
	
	reverse[i]='\0';
	
	printf("%s\n",reverse);
	
	return 0;
}

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

int main()
{
   char s[20], r[20];
   int n, c, d;
   gets(s);

   n = strlen(s);

   for (c=n-1,d=0;c>=0;c--,d++)
      r[d] = s[c];

   r[d] = '\0';

   printf("%s\n", r);

   return 0;
}

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

int main(){
	char str[20];
	scanf("%s",str);
	reverse(str,str + strlen(str));
	printf("%s",str);
	return 0;
}

C++: #include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main()
{
	char str[21] = "\0";
	int X;

	scanf("%s", str);

	for (X = strlen(str)-1; X > 0; X--)
	{
		if (X <= (strlen(str) - 1) - X)
			break; 

		str[(strlen(str)-1) - X] ^= str[X];
		str[X] ^= str[(strlen(str)-1) - X];
		str[(strlen(str)-1) - X] ^= str[X];
	}
	printf("%s\n", str);

	return 0;
}

C++: #include<bits/stdc++.h>
const long long INF = INT_MAX / 2;
const long long MOD = 1000000007;
const long double PI = 3.1415926;
#define FOR(i,r,n) for(ll i = (ll)(r); i < (ll)(n); i++)
#define RFOR(i,r,n) for(ll i=(ll)(n-1);i>=r;i--)
#define REP(i,n) FOR(i,0,n)
#define REP1(i,n) FOR(i,1,n)
#define RREP(i,n) RFOR(i,0,n)
#define ALL(x) x.begin(),x.end()
#define RALL(x) x.rbegin(),x.rend()
#define ll long long int
using namespace std;
ll ans = 0, sum = 0, n, k, cnt = 0, w, h;
string s;
vector<ll> v;
vector < pair<ll, ll > > vp;
vector<vector<ll> > vv(50, vector<ll>(50, INF));
vector<string> vs;
vector<char> vc;
set<ll> st;
map<char, ll> mp;

/*--------------------template--------------------*/

int main()
{
	cin >> s;
	RREP(i, s.size())
	{
		cout << s[i];
	}
	cout << endl;
}

C++: #include<stdio.h>
#include<string.h>
int main(void)
{
	int i,len;
	char s[20];
	scanf("%s",s);
    len=strlen(s);
	for(i=len-1;i>=0;i--){
	    printf("%c",s[i]);
	}
	    printf("\n");
	return 0;
}

C++: #include <iostream>
#include <vector>
#include <math.h>
#include <string>

int main(void);
std::string rev_string(std::string str);


int main(){
	std::string str = "";
	//char str[20];
	std::cin >> str;
	std::cout << rev_string(str);

	//while (1);
	return 0;
}

//*
std::string rev_string(std::string str){
	int i;
	int len = str.length();
	for (i = 0; i < len / 2; i++) {
		char temp = str[i];
		str[i] = str[len - i - 1];
		str[len - i - 1] = temp;
	}

	return str;
}
//*/

C++: #include <iostream>
#include <cstring>
using namespace std;
char ary[30];
int main(){
	cin>>ary;
	int N=strlen(ary);
	for(int i=N-1;i>=0;i--){
		cout<<ary[i];
	}
	cout<<endl;
	return 0;
}

C++: #include <iostream>
#include <cstring>
#include <cstdio>

using namespace std;

void sort(char *str){
	int len, len3 = 0;
	char str2[20], work; 
	len = strlen(str);

	for(int len2 = 0; len > len2; len2++){
		str2[len2] = str[len2];
	}

	for(len3 = 0, len = len - 1; len >= len3; len--,len3++){
		work = str[len];
		str[len] = str[len3];
		str[len3] = work;
	}
}

int main(){
	char str[20];
	while (cin >> str) {
		sort(str);
		cout << str << endl;
	}
}

C++: #include<bits/stdc++.h>
using namespace std;
int main(){
	string str;
	getline(cin >> ws, str);
	reverse(str.begin(), str.end());
	cout << str << endl;
}

C++: #include<iostream>
#include<string>
#include<string.h>
#include<algorithm>
#include<stdio.h>
#include<cmath>
#include<vector>
#include<utility>
#include<stack>
#include<queue>

#define FOR(i, a, b) for(int i=(a);i<=(b);i++)
#define RFOR(i, a, b) for(int i=(a);i>=(b);i--)
#define MOD 1000000007

using namespace std;

int main(void) {
	string s;
	cin >> s;

	RFOR(i, s.size() - 1, 0) {
		cout << s[i];
	}
	cout << endl;
	return 0;
}

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

int main(){
	int i,len;
	char str[20];

	cin >> str;

	len = strlen(str);

	for(i = len-1; i >= 0; i--)
		cout << str[i];

	cout << endl;

	return 0;
}

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

using namespace std;

int main(){
	char str[25];
	int i, num;
	
	cin >> str;

	num = strlen(str);

	for(i = num - 1; i >= 0; i --){
		cout << str[i];
	}
	cout << endl;
}

C++: #include <cstdio>
#include <cstring>
#include <algorithm>
using std::__gcd;
using std::sort;
int main(){
	char s[100];
	scanf("%s",s);
	int l = strlen(s);
	for(int i=l-1;i>=0;--i)
		putchar(s[i]);
	putchar('\n');
	return 0;	
}

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

using namespace std;

int main(){
	char line[20];
	int a=0;
	
while(cin>>line){
	for(a; line[a] != 0x00 ;a++);
	a--;
	for(a;a>=0;a--){
	cout<<line[a];
	}
	cout<<endl;
}


return 0;
}

C++: #include <stdio.h>
int main(void){
    char s[22]={'\n'},*p;
    gets(s+1);
    for(p=s;*p++;);
    for(p--;s<=p;p--)putchar(*p);
    return 0;
}

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

int main(){
    std::string str;
    std::queue<char> que;
    std::cin >> str;
    const int size = str.size();
    for(int i = 0; i < size; ++i){
        que.push(str.back());
        str.erase(str.size() - 1, 1);
    }
    for(int i = 0; i < size; ++i){
        std::cout << que.front();
        que.pop();
    }
    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];
	}
	cout<<endl;
	return 0;
}

C++: #include "bits/stdc++.h"
using namespace std;

long long int gcd(long long int l, long long int r) {
	assert(l > 0 && r > 0);
	if (l > r)return gcd(r, l);
	else {
		const long long int num = r%l;
		if (num) {
			return gcd(l, num);
		}
		else {
			return l;
		}
	}
}
long long int lca(long long int l, long long int r) {
	return l / gcd(l, r)*r;
}
int main() {
	string st; cin >> st;
	reverse(st.begin(), st.end());%
	return 0;
}

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

using namespace std;

#define loop(i,a,b) for(int i = a; i < b ; i ++)
#define rep(i,a) loop(i,0,a)

int main(void){
  string s;
  cin>>s;
  for(int i = s.size() - 1 ; i >= 0 ; i --){
    cout<<s[i];
  }
  cout<<endl;

}

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

int main() {
	int i;
	string s;
	cin >> s;
	for (i = 0; i <= 20; i++) {
		if (s[i] == 0)
			break;
	}
	for (i--; i >= 0; i--) {
		cout << s[i];
	}
	//cout << endl;
	return 0;
}

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

int main()
{
	string x;
	cin >> x;
		for(int i=x.length()-1;i>=0;i--)
			cout << x[i];
	cout<<"\n";
}

C++: #include <stdio.h>
int main(void){
    char s[21],*p;
    gets(s);
    for(p=s;*p++;);
    for(p--;s<=p;p--)putchar(*p);
    puts("");
    return 0;
}

C++: #include "bits/stdc++.h"
using namespace std;

int main()
{
    string a;
    char b;
    cin >> a;
    for (int i = 0; i < a.size() / 2; i++)
    {
        b = a[i];
        a[i] = a[a.size() - 1 - i];
        a[a.size() - 1 - i] = b;
    }
    cout << a << endl;
}

C++: #include<stdio.h>



int main(){
	char c[20];

	scanf("%s",c);
	int i;

	for(i=0;i<20;i++){
		if((int(c[19-i])!=-52)&&(int(c[19-i]!=0))){
			printf("%c",c[19-i]);
		}
	}


	return 0;
}

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!=-1;i--) {
    printf("%c", A[i]);
  }
}

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

int main()
{
  string a;
  cin>>a;
  for(int b=a.length()-1;b!=-1;b--){
    cout<<a[b];
  }
  cout<<endl;
  return 0;
}