Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func main() {
	for scanner.Scan() {
		var result string
		line := scanner.Text()
		key := make(map[string]string)

		var i int32
		for ; i < 52; i++ {
			makeKey(key, i)
			result = decode(key, line)

			if strings.Contains(result, "the") {
				break
			} else if strings.Contains(result, "this") {
				break
			} else if strings.Contains(result, "that") {
				break
			}
		}

		fmt.Println(result)
	}
}

func makeKey(key map[string]string, shift int32) {
	for i := 'a'; i <= 'z'; i++ {
		cipher := (i + shift)
		if cipher > 'z' {
			cipher = cipher%'z' + 'a' - 1
		} else if cipher < 'a' {
			cipher = cipher + ('z' - 'a') + 1
		}
		key[string(i)] = string(cipher)
	}
}

func decode(key map[string]string, cipher string) string {
	var result string
	for _, v := range cipher {
		if key[string(v)] != "" {
			result += key[string(v)]
		} else {
			result += string(v)
		}
	}
	return result
}

C++: #include <iostream>
#include <cstring>
#include <cstdio>
#include <cctype>
#define N 100
using namespace std;

void hukugou(char str2[]){
  int i;

  while(1){

    for(i = 0;str2[i] != '\0';i++){
      if(str2[i] != ' ' && str2[i] != '\n'){
	str2[i] = (str2[i] - 'a' + 1) % 26 + 'a';
      }
    }

    if(strstr(str2, "the") != NULL || strstr(str2, "this") != NULL || strstr(str2, "that") != NULL){
      cout << str2;
      break;
    }
  }

}

int main(){
  char str[N];

  fgets(str, sizeof(str), stdin);

  hukugou(str);

  return 0;
}

C++: #include <iostream>
#include <string>
using namespace std;
int main()
{
	string str,t;
	while(getline(cin,str))
	{
		for(int i = 1;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;

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

  getline( cin, str );

  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;
  }
  
  cout << str;

  return 0;
}

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

using namespace std;

int main() {
    string a;
    
    getline(cin,a);
    
    while (1){
        if(a.find("this")!=-1 || a.find("this")!=-1 || a.find("this")!=-1){
            break;
        }
        
        for(int i=0; i<a.length(); i++){
            if(a[i]==' '|| a[i]=='.'){
                
            }else if(a[i]=='z'){
                a[i]='a';
            }else{
                a[i]++;
            }
        }

    }
    cout<<a<<endl;;
    
    
    return 0;
}

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

int main(){
  string s;
  int cnt=0;

  while(getline(cin, s)){


    while(true){
      bool flag=false;

      for(int i=0;i<s.length();i++){
        string key1 = s.substr(i,3);
        string key2 = s.substr(i,4);
        if(key1 == "the" || key2 == "this" || key2 == "that"){
          flag = true;
          break;
        }
      }

      if(flag){
        cout << s << endl;
        break;
      }

      for(int i=0;i<s.length();i++){
        if(s[i] > 'a' && s[i] < 'z'){
          s[i] -= 'a';
          s[i] -= 1;
          if(s[i] < 0){
            s[i] += 'A' - 'a';
          }
          s[i] += 'a';
        }
      }
    }
  }
}

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

using namespace std;

void CaesarCipher(const string&);
int main(){
  string str;
  while(getline(cin,str)){
    CaesarCipher(str);
  }
}


void CaesarCipher(const string& str){
  string diffstr=str;
  while(diffstr.find("the")==string::npos&&
        diffstr.find("this")==string::npos&&
        diffstr.find("that")==string::npos ){
    for(int i=0;i<str.length();i++){
      diffstr[i]+=isalpha(str[i])?1:0;
    }
  }
}

C++: #include<iostream>
#include<algorithm>
#include<string>
#include<cstdio>
#include<cstring>
using namespace std;
int main(){
  string str;
  char s[256];
  int w = 0;
  while(scanf(" %c",&s[0]) != EOF{
    do {
      w++;
      scanf("%c",&s[w]);
    }while(s[w] != '\n');
    while(1){
      s[w+1] = '\0';
    
      for(int i=0;i<w;i++){
	if(s[i] != ' ' && s[i] != '.'){
	  s[i]++;
	  if(s[i]>'z')s[i] = s[i] - 'z' + 'a' - 1;
	}
      }
      if(strstr(s,"the") != NULL)break;
      if(strstr(s,"that") != NULL)break;
      if(strstr(s,"this") != NULL)break;
    }
    printf("%s",s);
    memset( s , 0 , sizeof(s) );
  }
}

C++: 
using namespace std;
int main(){
  char str;
  while(1){
    str = getchar();
    if(str=='.'){
      cout<<str;
      break;
    }
    if(str!=' '){
      str=str-4;
      cout<<str;
    }else{
      cout<<" ";
    }
  }
  cout<<endl;
  return 0;
}

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

int main(){
  int index ,flag=0 ,temp= 'z' - '`';
  string s ,key[3]={ "the" ,"this" ,"that" };

  while( true ){
    flag = 0;
    getline( cin ,s );
    if( cin.eof() ){
      break;
    }

    while( true ){
      for( int i=0 ; i<s.length() ; i++ ){ // シーザー暗号を戻す
	if( s[i] != '.' && s[i] != ' ' && s[i] != '\n' ){ //　記号はスルー
	  s[i]--;
	  if( s[i] < 'a' ){ // aからzに飛ばす
	    s[i] += temp; 
	  }
	}
      }
      
      for( int i=0 ; i<3 ; i++ ){
	index = s.find( key[i] ,0 ); // the ,this ,that を探す
	if( index != string::npos ){ // あった場合
	  cout << s << endl;
	  flag = 1;
	  cin.ignore();
	  break;
	}
      }
      if( flag == 1 ){
	break;
      }
    }
  }
}

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

int main(){
  string s;
  while(1){
    getline(cin,s);
    if(cin.eof()) break;
    for(int i=0;i<25;i++){
      if((s.find("this")!=string::npos) || (s.find("that")!=string::npos) || (s.find("the")!=string::npos)) break;
      for(int j=0;j<=s.size();j++){
	if(s[j] >= 'a' && s[j] <= 'y') s[j]++;
	else if(s[j] == 'z') s[j]='a';
      }
    }
    cout << s << endl;
  }
}

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

string arrs[200];

bool judge4(const string &str) {
	int d1 = str[0] - 't';
	int d2 = str[1] - 'h';
	int d3 = str[2] - 'i';
	int d4 = str[3] - 's';
	int d5 = str[2] - 'a';
	int d6 = str[3] - 't';
	return (d1 == d2 && ((d2 == d3 && d3 == d4) || (d2 == d5 && d3 == d6)));
}

bool judge3(const string &str) {
	int d1 = str[0] - 't';
	int d2 = str[1] - 'h';
	int d3 = str[2] - 'e';
	return (d1 == d2 && d2 == d3);
}

int main() {
	cin.clear();
	int cnt = 0;
	while (!cin.eof()) {
		cin >> arrs[cnt++];
		char ch = getchar();
		if (ch == '\n') {
			bool isOk = 0;
			int delta = 0;
			for (int i = 0; i < cnt; ++i) {
				if (arrs[i].length() == 4) {
					if (judge4(arrs[i])) {
						isOk = 1;
						delta = arrs[i][0] - 't';
						break;
					}
				}else if (arrs[i].length() == 3) {
					if (judge3(arrs[i])) {
						isOk = 1;
						delta = arrs[i][0] - 't';
						break;
					}
				}
			}
			for (int i = 0; i < cnt; ++i) {
				for (int j = 0; j < arrs[i].length(); ++j) 
					if (arrs[i][j] != '.') arrs[i][j]-= delta;
				cout << arrs[i] << ((i == cnt - 1) ? "\n" : " ");
			}
			cnt = 0;
		}
	}
	return 0;
}