Go: package main

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

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 reflect.DeepEqual(infos, []string{}) {
			break
		}
		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 main()
{
  string stro, str;
  while(getline(cin, stro)){
    for(int i = 1; i < 26; i++){
      str = stro;
      for(int j = 0; j < stro.length(); j++){
	if(str[j] != ' ' && str[j] != '.' && str[j] != '\n')
	  if(str[j] + i > 'z')
	    str[j] += i - 26;
	  else
	    str[j] += i;
      }
      if(str.find("the ", 0) != string::npos || str.find("this ", 0) != string::npos || str.find("that ", 0) != string::npos || str.find(" the.", 0) != string::npos || str.find(" this.", 0) != string::npos || str.find(" that.", 0) != string::npos || str.find(" the ", 0) != string::npos || str.find(" this ", 0) != string::npos || str.find(" that ", 0) != string::npos)
	  cout << str << endl;	
    }
  }
}

C++:  
  #include<iostream>
 #include<stdio.h>
 #include<string>
 #include<math.h>
 #include<iomanip>
 #include<algorithm>
 #include<string.h>
 #include<cctype>
 #include<map>
 #include<set>
 #include<vector>
 #include<sstream>
 #include<stack>
 
 using namespace std;
  
 int main()
 {
   string a,b;
   while(cin>>a)
   {
     for(int i=0;i<a.length();i++)
     {
       if(a[i]>='a'&&a[i]<='z')
       { 
         char temp= a[i]<'e' ? (a[i]+26-4): (a[i]-4);
         b+=temp;
       }         
       else b+=a[i]; 
     }             
     cout<<b<<endl;
   }
   //while(1);      
   return 0;    
 }

C++: #include <iostream>
#include <sstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <climits>
#include <cfloat>
using namespace std;

int main()
{
    for(;;){
        string s;
        getline(cin, s);
        if(s == "")
            return 0;
    
        int n = s.size();
        for(;;){
            bool bl=false;
            for(int i=0; i<n; ++i){
               if('a' <= s[i] && s[i] <= 'z'){
                   if(s[i] == 'z')
                           s[i] = 'a';
                   else
                           ++ s[i];
               }
           }
           istringstream iss(s);
           string s1;
           while(iss >> s1){
               if(s1 == "the" || s1 == "this" || s1 == "that"){
                       cout << s << endl;
                       bl=true;
                       break;
               }
            }
           if(bl) break;
         }      
    }
}

C++: #include <iostream>
#include <string>
using namespace std;
int main()
{
	string str,t;
	while(getline(cin,str))
	{
		for(int i = 0;i < 26;++i)
		{
			t = str;
			for(int j = 0;j < str.size();++j)
			{
				if(t[j] == ' ' || t[j] == '.') continue;
				t[j] = (t[j] - 'a' + i) % 26 + 'a';
			}
			if(t.find("that",0) != string::npos || t.find("this",0) != string::npos || t.find("the",0) != string::npos){
				cout << t << endl;
				break;
			}
		}
	}
	return 0;
}

C++: #include<iostream>
#include<string>
#include<vector>
using namespace std;
char CaesarChar(char );
string CaesarString(string s);
vector<string> CaesarVector(vector<string> v);
vector<string> SolveCaesar(vector<string> v);
int main() {
  string s;
  while( getline(cin,s)) {  
    vector<string> array;
    int space=0;
    int next_space=0;    
    for(int i=0;i<(int)s.size();i++) {
      if(s[i]== ' '){
	next_space=i;
	string tmp="";
	for(int j=space;j<next_space;j++)
	  tmp+=s[j];
	space=next_space+1;
	array.push_back(tmp);
      }
    }
    string tmp="";
    for(int i=next_space+1;i<(int)s.size();i++) 
      tmp+=s[i];
    array.push_back(tmp);
    vector<string> answer=SolveCaesar(array);
    for(int i=0;i<(int)answer.size();i++)
      cout<<answer[i]<<" "; 
    cout<<endl;
  }
  return 0;
}
char CaesarChar(char c) {
  if(c=='z')
    return 'a';
  return char(c+1);
}
string CaesarString(string s) {
  string tmp="";
  for(int i=0;i<(int)s.size();i++)
    tmp+=CaesarChar(s[i]);
  return tmp;
}
vector<string> CaesarVector(vector<string> v) {
  vector<string> tmp;
  for(int i=0;i<(int)v.size();i++) 
    tmp.push_back(CaesarString(v[i]));
  return tmp;
}
vector<string> SolveCaesar(vector<string> v) {
  for(int i=0;i<(int)v.size();i++) {
    if(v[i]=="the" || v[i]=="this" || v[i]=="that")
      return v;
  } 
  return SolveCaesar(CaesarVector(v));
}

C++: #include<iostream>
#include<string>
int main(){
	std::string str;
	while(std::getline(std::cin,str)){
	for(int i=0;i<str.size();i++){
		if(str[i]!=' '&&str[i]!='z'&&str[i]=='.')str[i]+=1;
		if(str[i]=='z')str[i]-=25;
	}
	std::cout<<str<<std::endl;
	}
	return 0;
}

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

int main(){

	char s[1000];
	while (gets(s)){
		
		int diff;
		int flag = false;
		//一番最初に｛the,that,this｝がある場合
		diff = s[0] - 't';
		if ((s[1] - diff) == 'h'){
			//printf("%c\n", s[j+1] - diff);
			if ((s[2] - diff) == 'e'){
				//printf("%c\n", s[j + 2] - diff);
				if (s[3] == ' '){
					flag = true;
				}
			}
			else if ((s[2] - diff) == 'a'){
				//printf("%c\n", s[j + 2] - diff);
				if ((s[3] - diff) == 't'){
					//printf("%c\n", s[j + 3] - diff);
					if (s[4] == ' '){
						flag = true;
					}
				}
			}
			else if ((s[2] - diff) == 'i'){
				//printf("%c\n", s[j + 2] - diff);
				if ((s[3] - diff) == 's'){
					//printf("%c\n", s[j + 3] - diff);
					if (s[4] == ' '){
						flag = true;
					}
				}
			}
		}

		if (!flag){
			//一番以降に｛the,that,this｝がある場合
			for (int j = 1; j < strlen(s); j++){
				if ((s[j]) == ' '){
					diff = s[j + 1] - 't';
					if ((s[j + 1] - diff) == 't'){
						//printf("diff:%d\n", diff);
						if ((s[j + 2] - diff) == 'h'){
							//printf("%c\n", s[j+1] - diff);
							if ((s[j + 3] - diff) == 'e'){
								//printf("%c\n", s[j + 2] - diff);
								if (s[j + 4] == ' '){
									break;
								}
							}
							else if ((s[j + 3] - diff) == 'a'){
								//printf("%c\n", s[j + 2] - diff);
								if ((s[j + 4] - diff) == 't'){
									//printf("%c\n", s[j + 3] - diff);
									if (s[j + 5] == ' '){
										break;
									}
								}
							}
							else if ((s[j + 3] - diff) == 'i'){
								//printf("%c\n", s[j + 2] - diff);
								if ((s[j + 4] - diff) == 's'){
									//printf("%c\n", s[j + 3] - diff);
									if (s[j + 5] == ' '){
										break;
									}
								}
							}

						}
					}
				}
			}
		}
		//printf("diff:%d\n",diff);
		for (int i = 0; i < strlen(s); i++){
			if (s[i] == ' ' || s[i] == '.')continue;
			s[i] -= diff;
		}
		//s[strlen(s) - 1] = '\n';
		printf("%s\n", s);
	}
	return 0;
}