Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

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 {
		infos := strings.Split(nextString(), " ")
		plain := make([]string, len(infos))
		if len(infos) == 0 {
			break
		}
		// 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 <bits/stdc++.h>

using namespace std;

bool is_finish(string s)
{
    string str;
    stringstream ss(s);
    while (ss >> str) {
        if (str == "the" ||
            str == "this" ||
            str == "that") return 1;
    }
    return 0;
}

int main()
{
    string s;
    while (getline(cin, s)) {
        s.pop_back();
        for (int i = 0; i < 26; i++) {
            for (char &c: s) {
                if (islower(c)) {
                    c = c + 1;
                    if (c > 'z') c = 'a';
                }
            }
            if (is_finish(s)) {
                break;
            }
        }
        cout << s << "." << endl;
    }
    return 0;
}

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


int main()
{
	string s, line[81];
	int counter = 0;
	getline(std::cin, s);
	s += "\n";

	//入力内容を配列にとる．
	string word = "";
	for (int i = 0; i < (signed)s.length(); i++){
		if (s[i] == ' ' || s[i] == '\n'){
			line[counter++] = word;
			word = "";
		}
		else{
			word += s[i];
		}
	}

	

	//ずらす数を探す
	int slide;
	for (int i = 0; i <= 26; i++){
		for (int j = 0; j < counter; j++){
			string word = "";
			for (int k = 0; k < (signed)line[j].length(); k++){
				if (line[j][k] != '.' && line[j][k] != ' '&& line[j][k] != '\n'){
					word += 'a' + (line[j][k] + i - 'a') % 26;
				}
				else{
					word += line[j][k];
				}
			}
			if (word == "the" || word == "this" || word == "that"){
				slide = i;
				goto jump;
			}

		}
	}

jump:

	//ずらすべき数だけずらす
	for (int i = 0; i < counter; i++){
		for (int j = 0; j <(signed)line[i].length(); j++){
			if (line[i][j] != '.' && line[i][j] != ' '&& line[i][j] != '\n'){
				line[i][j] = 'a' + (line[i][j] + slide - 'a') % 26;
			}
		}
	}

	//出力
	for (int i = 0; i < counter - 1; i++){
		cout << line[i] << " ";
	}
	cout << line[counter - 1] << endl;


	return 0;
}

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

int main ()
{
    int i,j;
    char a[10000];
    while(gets(a)!=NULL)
    {
        int len=strlen(a);
        int x=a[0]-'t';
        for(i=0;i<len;i++)
        {
            if(a[i]>='a' && a[i]<='z')
            printf("%c",a[i]-x);
            else
                printf("%c",a[i]);
        }
        printf("\n");
    }
    return 0;
}

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

int main(void){
  int len, cnt;
  string str(" "), buf;

  getline( cin, buf );
  if( buf[buf.size()-1] == '\n' )
    buf.erase(buf.size()-1);
  if( buf[buf.size()-1] == '\r' )
    buf.erase(buf.size()-1);
  
  str.append(buf);
  str.append(" ");
  len = str.length();
  cnt = 0;

  while(true){
    if( str.find(" the ", 0) != string::npos
	|| str.find(" this ", 0) != string::npos 
	|| str.find(" that ", 0) != string::npos
	)
      break;
    for(int i = 0; i < len; i++){
      if( 'a' <= str[i] && str[i] <= 'z' ){
	str[i]++;
	if(str[i] > 'z')
	  str[i] = 'a';
      }
    }

    cnt++;
    if(cnt > 30)
      break;
  }
  
  str.erase(0,1);
  str.erase(str.size() - 1);
  cout << str << endl;

  return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <string>
using namespace std;
int main() {
	string str;
	while(getline(cin, str)) {
		int n = 't' - str[0];
		for(int i = 0; str[i] != '\0'; i++) {
			if(('a' <= str[i])&&(str[i] <= 'z')) {
				str[i] += n;
				if(str[i] > 'z') {
					str[i] -= 'z';
				}
			}
		}
		cout << str << endl;
	}
	return 0;
}

C++: #include<iostream>

int isThisOrThatOrThe(std::string s){
  int dif=0;
  char cro = s[0];
  while(true){
    if(cro == 't')break;
    cro+=1;
    if(cro > 'z')cro = 'a';
    dif++;
  }
  std::string cpys;
  for(int i=0;i<s.length();i++){
    if(s[i]+dif > (int)'z')cpys += (char)((s[i]+dif)%123+'a'); 
    else cpys += (char)(s[i] + dif);
  }
  if(cpys == "that" || cpys == "this" || cpys == "the")return dif;
  return -1;
}


int main(){
  std::string s;
  while(getline(std::cin,s,'\n')){
    
    bool piri = false;
    int st=0,dif = -12;
    for(int i=0;i<=s.length();i++){
      if(s[i] == ' ' || i == s.length() || s[i] == '.'){
	dif = isThisOrThatOrThe(s.substr(st,i-st));
	if(dif != -1){
	  break;
	}
	st = i+1;
      }
    }

    for(int i=0;i<s.length();i++){
      if(s[i] == ' ' || s[i] == '.'){
	std::cout << s[i];
	continue; 
      }
      s[i]+dif > (int)'z'?std::cout << (char)((s[i]+dif)%123+'a'):std::cout << (char)(s[i]+dif);
    }
    std::cout << std::endl;
  }
  return 0;
}

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

using namespace std;

string str;

bool caesar()
{
	bool flag = false;

	for (int i=0; i<(int)str.size() - 2; i++)
	{
		if(str[i] == 't' && str[i+1] == 'h') {
			if(str[i+2] == 'e' && (str[i+3] == ' ' || str[i+3] == '\0' || str[i+3] == '.')) {
				flag = true;
				break;
			}
			if(str[i+2] == 'i' && str[i+3] == 's' && (str[i+4] == ' ' || str[i+4] == '\0' || str[i+4] == '.')) {
				flag = true;
				break;
			}
			if(str[i+2] == 's' && str[i+3] == 't' && (str[i+4] == ' ' || str[i+4] == '\0' || str[i+4] == '.')) {
				flag = true;
				break;
			}
		}
	}

	return flag;
}


int main()
{
	while(getline(cin, str))
	{
		for (int i=0; i<26; i++)	//0〜25文字ずれるまで繰り返す
		{
			if(caesar()) {
				cout << str << endl;
			}

			//cout << str << endl;	//Debug

			for (int j=0; str[j] != '\0'; j++) {
				if(str[j] != ' ' && str[j] != '.') {
					if(str[j] == 'z') {
						str[j] = 'a';
					}
					else {
						str[j]++;
					}
				}
			}
		}
	}

	return 0;
}

C++: #include <iostream>
#include <string>
using namespace std;
int main()
{
	string str;
	while(getline(cin,str))
	{
		bool flag=false;
		for(int k=0;k<26;k++)
		{
			int i=0;
			for(i=0;i<str.size();i++)
			{
				if(str[i]-'a'<0 || str[i]-'z'>0) continue;
				else { str[i]++; if(str[i]-'z'>0) str[i]-=26; }
			};
			string ptr,qtr;
			for(i=0;i<str.size();i++)
			{
				if(i+4<str.size()) ptr=str.substr(i,4);
				if(i+3<str.size()) qtr=str.substr(i,3);
				if(ptr=="this" || ptr=="that" || qtr=="the") {flag=true; break;}
			};
			if(flag==true) break;
		};
		cout << str << endl ;
	}
}

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

int main(){

  string s;

  while(getline(cin,s)){
    while(s.find("the")==string::npos && s.find("this")==string::npos && s.find("that")==string::npos){
      for(int i=0; i<s.size(); i++){
        if('a'<=s[i]&&s[i]<='y')
          s[i] ++;
        else if(s[i]=='z'){
          s[i]='a';
        }
      }
    }
    cout << s << endl;
  }


  return 0;
}