Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func cipher(text string, direction int, int_shift int) string {
	shift, offset := rune(int_shift), rune(26)
	runes := []rune(text)
	for index, char := range runes {
		switch direction {
		case 1:
			if char >= 'a' && char <= 'z'-shift || char >= 'A' && char <= 'Z'-shift {
				char = char + shift
			} else if char > 'z'-shift && char <= 'z' || char > 'Z'-shift && char <= 'Z' {
				char = char + shift - offset
			}
		case -1:
			if char >= 'a'+shift && char <= 'z' || char >= 'A'+shift && char <= 'Z' {
				char = char - shift
			} else if char >= 'a' && char < 'a'+shift || char >= 'A' && char < 'A'+shift {
				char = char - shift + offset
			}
		}
		runes[index] = char
	}
	return string(runes)
}

func main() {
	for scanner.Scan() {
		infos := strings.Split(scanner.Text(), " ")
		plain := make([]string, len(infos))
		// fmt.Println(infos)
		Decryption:
			for i := 0; i < 26; i++ {
				for j := range infos {
					plain[j] = cipher(infos[j], 1, i)
				}
				for j := range plain {
					if plain[j] == "this" || plain[j] == "that" || plain[j] == "the" {
						break Decryption
					}
				}
			}
			fmt.Println(strings.Join(plain, " "))
	}
}

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

int checkCaesarChipher(string str1, string str2){
	int a[1000],b[1000];
	bool flag = false;
	
	for(unsigned int i=0 ; i<str1.size()-1 ; i++){
		a[i] = (str1[0] - str1[i] + 26 - 'a') % 26;
		b[i] = (str2[0] - str2[i] + 26 - 'a') % 26;
		if(a[i]==b[i]){
			flag = true;
		}else{
			flag = false;
			break;
		}
	}
	if(flag){
		return (str2[0] - str1[0]);
	}else{
		return 0;
	}
}

int main(){
	string str[400];
	int i=0, ans=0;
	while(cin >> str[i]){
		
		i++;
		//if( str[i-1][str[i-1].size()-1]=='.') break;
	}
	for(int j=0 ; j<i ; i++){
		ans = 0;
		if(str[j].size()==3){
			string hoge1 = "the";
			if(checkCaesarChipher( hoge1 , str[j] )!=0){
				ans = checkCaesarChipher( hoge1 , str[j] );
				break;
			}
		}
		if(str[j].size()==4){
			string hoge2 = "that";
			if(checkCaesarChipher( hoge2 , str[j] )!=0){
				ans = checkCaesarChipher( hoge2 , str[j] );
				break;
			}
			string hoge3 = "this";
			if(checkCaesarChipher( hoge3 , str[j] )!=0){
				ans = checkCaesarChipher( hoge3 , str[j] );
				break;
			}
		}
	}
	if(ans!=0){
		for(int j=0 ; j<i ; j++){
			for(unsigned int k=0 ; k<str[j].size() ; k++){
				if(str[j][ str[j].size()-1] != '.'){
					str[j].at(k) -= ans;
				}
			}
			if(j==i-1) cout << str[j] << endl;
			else cout << str[j] << " ";
		}
	}
	return 0;
}

C++: #include <stdio.h>

int main(void)
{
	char str[80];
	int num, num2;
	int i;
	
	while (fgets(str, 80, stdin) != NULL){
		num = 't' - str[0];
		i = 0;
		while (str[i] != '\0'){
			if (str[i] != '.' && str[i] != ' ' && str[i] != '\n'){
				str[i] += num;
				if (str[i] > 'z'){
					num2 = str[i] - 'z';
					str[i] = num2 + 'a' - 1;
				}
				else if (str[i] < 'a'){
					num2 = 'a' - str[i];
					str[i] = 'z' - num2 + 1;
				}
			}
			i++;
		}
		printf("%s", str);
	}
	
	printf("\n");
	
	return (0);
}

C++: #include <bits/stdc++.h>

using namespace std;

typedef unsigned long long ull;
#define loop(i,a,b) for(int i=(a);i<ull(b);++i)
#define rep(i,n) loop(i,0,n)
#define all(a) (a).begin(), (a).end()

const double eps = 1e-10;
const double pi  = acos(-1.0);
const double inf = (int)1e8;

int main(){
	string s;
	getline(cin, s);
	while(true){
		for(int i=0; i< s.size(); i++) if(s[i] == 'z') s[i] = 'a';  else if('a' <= s[i] && s[i] <= 'z')s[i]++;
		bool possible = false;
		for(int i=0; i< s.size(); i++){
			if(s.substr(i, 3) == "the" || s.substr(i, 4) == "this" || s.substr(i, 4) == "that"){
				cout << s << endl;
				return 0;
			}
		}
	}
}

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

bool is_contain_keywords(string str,vector<string>& keywords) {
  vector<string>::iterator key_itr = keywords.begin();
  while(key_itr != keywords.end()) {
    if(str.find(*key_itr) != string::npos) {
      return true;
    }
    key_itr++;
  }
  return false;
}

string decode(string cipher) {
  vector<string> keywords;
  keywords.push_back("the");
  keywords.push_back("this");
  keywords.push_back("that");

  for(int shift = 0;shift < 'z' - 'a';shift++) {
    int str_len = cipher.length();
    string str = cipher;
    for(int i=0;i<str_len;i++) {
      if('a' < cipher[i] && cipher[i] < 'z') {
        str[i] = (cipher[i] - 'a' + shift) % ('z' - 'a') + 'a';
      }
    }
    if(is_contain_keywords(str,keywords)) return str;
  }
  return "";
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);

  string cipher;
  getline(cin,cipher);
  cout << decode(cipher) << endl;
}

C++: #include<iostream>
#include<string>
using namespace std;
string S; char T[29] = "abcdefghijklmnopqrstuvwxyz. "; int x[100000];
int main() {
	getline(cin, S);
	for (int i = 0; i < 100000; i++) { x[i] = 100000; }
	for (int i = 0; i < S.size(); i++) {
		for (int j = 0; j < 28; j++) {
			if (T[j] == S[i]) {
				x[i] = j;
			}
		}
	}
	for (int i = 0; i < 26; i++) {
		for (int i = 0; i < S.size(); i++) {
			if (x[i] == 19 && x[i + 1] == 7 && x[i + 2] == 8 && x[i + 3] == 18) {
				goto E;
			}
			if (x[i] == 19 && x[i + 1] == 7 && x[i + 2] == 0 && x[i + 3] == 18) {
				goto E;
			}
			if (x[i] == 19 && x[i + 1] == 7 && x[i + 2] == 4) {
				goto E;
			}
		}
		for (int i = 0; i < S.size(); i++) {
			if (x[i] < 26) {
				x[i]++;
				x[i] %= 26;
			}
		}
	}
E:;
	for (int i = 0; i < S.size(); i++) {
		cout << T[x[i]];
	}
	cout << endl;
}

C++: #include <iostream>
#include <complex>
#include <cmath>
#include <cstdio>
#include <string>
#include <sstream>

using namespace std;

string rotate(string str) {
    for (int i = 0; i < str.size(); i++) {
        if ('a' <= str[i] && str[i] < 'z')str[i]++;
        else if (str[i] == 'z')str[i] = 'a';
    }
    return str;
}

int main() {
    string str;
    while(getline(cin, str)) {
        for (int i = 0; i < 26; i++) {
            str = rotate(str);
            /*
            string tmp;
            bool flg = false;
            for (int i = 0; i < str.size(); i++) {
                if (str[i] != '.')tmp += str[i];
            }
            stringstream ss(tmp);
            while(ss >> tmp) {
                if (tmp == "the" || tmp == "this" || tmp == "that")flg = true;
                break;
            }
            if (flg) {
                cout << str << endl;
                break;
            }
            */
            if (str.find("the") != string::npos ||
                str.find("this") != string::npos ||
                str.find("that") != string::npos) {
                cout << str << endl;
                break;
            }
        }
    }
    return 0;
}