Go: package main

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

var sc = bufio.NewScanner(os.Stdin)

func read() string {
	sc.Scan()
	return sc.Text()
}

func main() {
	sc.Split(bufio.ScanLines)
	s := read()
	rv := ""
	cols := strings.Split(s, "")
	for i := 0; i < len(cols); i++ {
		rv += cols[len(cols)-1-i]
	}
	fmt.Println(rv)
}

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

int main()
{
    char str[21];
    char str121];
    int l=0;
    cin>>Str;
    for(int i=0;str[i]!='\0';)
        i++;
    for(int k=i-l;k>=0;k--,l++)
    {
        cout<<str[k];
    }
    cout<<endl;
    return 0;
}

C++: #include<iostream>

#define     MAX_LENGTH     30

using namespace std;

int main(){
	char str[MAX_LENGTH];
	int i,n;

	// 入力
	cin >> str;

	// 文字数計測
	for(n=0;(str[n] != '\n') && (str[n] != '\0');n++){
	}

	// 逆順出力
	for(i = (n - 1);i>=0;i--){
		cout << str[i];
	}
	cout << endl;

	return 0;
}

C++: #include <stdio.h>
#include <string.h>
int main() {char Tex[25];scanf("%s",&Tex);for (int j=strlen(Tex)-1;j>=0;printf("%c",Tex[j--]));puts("");return 0;}

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

int main()
{
	char s[21];
	cin.getline(s, 21, '\n');
	int l = strlen(s);
	for (int i = l - 1; i >= 0; i--)
		cout << s[i];
	return 0;
}

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

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

C++: #include<iostream>
#include<string>
using namespace std;
int main(){
	string s;
	cin >> s;
	if(s.size()<=20){
		for(int i=s.size();i>=0;i--){
			cout << s[i-1];
		}
		cout << endl;
	}
	return 0;
}

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

typedef long long ll;
#define MAX 12345
#define rep(i,a,b) for(int i=a;i<=b;i++)
#define rev(i,a,b) for(int i=a;i>=b;i--)

int main()
{
    string str;

    while(cin>>str){
        ll l=str.size();
        while(l--){
            cout << str[l];
        }
        cout << endl;
    }

    return 0;
}

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

using namespace std;


int main(){
    string str;
    cin >> str;
    int n =str.size();
    
    for(int i=n-1; i>=0; i--){
        printf("%c",str[i]);
    }
    printf("\n");
}

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

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

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

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

C++: #include<bits/stdc++.h>
using ll = long long;
using namespace std;

int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	//cout << fixed << setprecision(15);
	string s;cin >> s;
	for(int i = s.length()-1; i >= 0; i--){
		cout << s[i];
	}
	cout << endl;

	return 0;
}

C++: process.stdin.resume();
process.stdin.setEncoding('utf8');
// Here your code !

process.stdin.on("data",function(chunk){
    console.log(chunk.split("").reverse().join())
})

C++: #include <iostream>
#include <string>
using namespace std;
int main() {
    string str; cin >> str;
    string::reverse_iterator rit = str.rbegin();
    while (rit != str.rend()) {
        cout << *rit;
        ++ rit;
    }
    cout << endl;
    return 0;
}

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

using namespace std;

class range {
private:
  struct Iterator {
    int val, inc;
    int operator*() {return val;}
    bool operator!=(Iterator& itr) {return val != itr.val;}
    void operator++() {val += inc;}
  };
  Iterator i, n;
public:
  range(int n) : i({0, 1}), n({n, 1}) {}
  range(int i, int n) : i({i, 1}), n({n, 1}) {}
  range(int i, int inc, int n) : i({i, inc}), n({n, inc}) {}
  Iterator& begin() {return i;}
  Iterator& end() {return n;}
};

template<class T> inline T at(const vector<T> &v, int i) {return v[(i % (int)v.size() + v.size()) % v.size()];}

template<class T> inline bool is_max(T &a, const T &b) {return a < b ? a = b, true : false;}
template<class T> inline bool is_min(T &a, const T &b) {return a > b ? a = b, true : false;}

int main() {
  string str;
  cin >> str;
  reverse(str.begin(), str.end());
  cout << str << endl;
}

C++: // @BEGIN_OF_SOURCE_CODE

#include <iostream>
#include <cstring>

using namespace std;

int main ()
{
    char str [20 + 10];

    scanf ("%d", str);

    int length = strlen(str);
    
    for ( int i = length - 1; i >= 0; i-- ) 
        printf ("%c", str [i]);
    
    printf ("\n");

    return 0;
}

// @END_OF_SOURCE_CODE

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

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

  std::reverse(str.begin(), str.end());
  std::cout << str << std::endl;

  return 0;
}

C++: #include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<ctime>
#include<cctype>
#include<climits>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<memory>
#include<functional>

#define REP(i, n) for(int i = 0;i < n;i++)
#define REPR(i, n) for(int i = n;i >= 0;i--)
#define FOR(i, m, n) for(int i = m;i < n;i++)
#define FORR(i, m, n) for(int i = m;i >= n;i--)
#define SORT(v, n) sort(v, v+n);
#define VSORT(v) sort(v.begin(), v.end());
#define llong long long
#define pb(a) push_back(a)
#define INF 999999999
using namespace std;

typedef vector<int> vi;
typedef vector<long long> vl;
typedef vector<double> vd;
typedef pair<int, int> pii;
typedef pair<long, long> pll;
typedef long long ll;

int dy[] = { 0, 0, 1, -1, 0 };
int dx[] = { 1, -1, 0, 0, 0 };

int main(){
	ios::sync_with_stdio(false);

	string str, str_r;

	cin >> str;
	reverse(begin(str), end(str));

	cout << str << endl;
		
}

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

using namespace std;


int main(){
	char mozi[20];
	int last;
	scanf("%s",mozi);

	for(int i=0;mozi[i] != '\0';i++){
		last = i;
	}

	for(int i=last;0 <= i;i--){
		printf("%c",mozi[i]);
	}

	printf("\n");

	return 0;
}

C++: #include <string.h>
#include <iostream>
#include <iomanip>
#include <list>
#include <map>
#include <algorithm>
#include <stack>

using namespace std;


int main(){
	char str[20];
	int j = 0;
	memset(str,'\0',sizeof(str));
	while(cin >> str){	
		for(int i = sizeof(str) / sizeof(char) - 1; i >= 0; i--){
			if(str[i] != '\0'){
				cout << str[i];
			}
		}
		cout << endl;
	}

	return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>
#include <cassert>
#include <vector>
#include <string>
#include <cmath>
#include <map> 
#include <sstream>
#include <cstdio>
#include <complex>
#include <cstring>
using namespace std;
 
const int MAX= 10000100;

#define loop(i,a,b) for(int i = a ; i < b ; i ++)
#define rep(i,a) loop(i,0,a)
#define all(a) (a).begin(),(a).end()
#define ll long long int
#define gcd(a,b) __gcd(a,b)
#define pb(a) push_back(a)
int GCD(int a, int b) {if(!b) return a; return gcd(b, a%b);}
int lcm(int a, int b) {return a*b / gcd(a, b);}

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>
#include<algorithm>
using namespace std;
int main(){
    string s;cin >> s;
    reverse(s.begin(), s.end());
    cout << s << endl;
}

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

using namespace std;

int main (int argc, char * const argv[]) {
    // insert code here...
    string str;
	cin >> str;
	reverse(str.begin(), str.end());
	cout<<str<<endl;
	
	return 0;
}

C++: #include<iostream>
#include<cstring>
using namespace std;
	
int main()
{
	int u;
	char str[19];
	cin>>str[19];
	int j=strlen(str);
	for(int i=j;i>=0;i--){
	cout<<"str[i]";
	}
        cout<<'\n';
	return 0;
}