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<iostream>
#include<vector>
#include<string>
#include<sstream>
int main()
{
	std::vector<std::string>result;
	for (std::string s; std::getline(std::cin, s);)
	{
		int delta;
		std::stringstream ss;
		ss << s;
		while (!ss.eof())
		{
			std::string temp;
			ss >> temp;
			if (temp.length() == 3 && temp[0] != '.' && temp[1] != '.' && temp[2] != '.')
			{
				int d1 = temp[0] - temp[1];
				int d2 = temp[1] - temp[2];
				if (d1 == 't' - 'h' && d2 == 'h' - 'e')
				{
					delta = temp[0] - 't';
					break;
				}
			}
			else if (temp.length() == 4 && temp[0] != '.' && temp[1] != '.' && temp[2] != '.' && temp[3] != '.')
			{
				int d1 = temp[0] - temp[1];
				int d2 = temp[1] - temp[2];
				int d3 = temp[2] - temp[3];
				if (d1 == 't' - 'h' && (d2 == 'h' - 'i' && d3 == 'i' - 's' || d2 == 'h' - 'a' && d3 == 'a' - 't'))
				{
					delta = temp[0] - 't';
					break;
				}
			}
		}
		result.push_back(std::string(s.length(), 'a'));
		for (int i = 0; i < s.length(); i++)
		{
			result.back()[i] = s[i] != '.' && s[i] != ' ' ? (s[i] - delta - 'a') % 26 + 'a' : s[i];
		}
	}
	for (auto i : result)
	{
		std::cout << i << std::endl;
	}
	return 0;
}

C++: //#define _USE_MATH_DEFINES
//#include <cmath>
#include <iostream>
//#include <stdio.h>
//#include <stdlib.h>
//#include <iomanip>
#include <vector>
#include <string>
//#include <algorithm>
//#include <functional>
//#include <time.h>
#include <sstream>

using namespace std;

bool isthe(string str){
	//?????????????????????????????? the this that?????¢??? ????????°ture

	int d1, d2, d3;

	d1 = (str[1] - str[0] + 26) % 26;

	if (d1 != 14){
		return false;
	}
	else{
		d2 = (str[2] - str[0] + 26) % 26;
		if (d2 != 11 && d2 != 15 && d2 != 7){
			return false;
		}
		else{
			if (d2 == 11 && str.size() == 3){
				return true;
			}
			else{
				d3 = (str[3] - str[0] + 26) % 26;
				if (d2 == 15 && d3 == 25) return true;
				if (d2 == 7 && d3 == 26) return true;
			}
		}
	}

	return false;

}


int main(){
	
	string s,sc, buf;
	stringstream ss;
	vector <string> as;
	int dif = 0;


	while (getline(cin, s)){
		dif = 0;
		buf = "";
		sc = "";
		ss.str("");
		ss.clear();

		sc += s;
		for (int i = 0; i < sc.size(); i++){
			if (sc[i] == '.')sc[i] = ' ';
		}
		ss << sc;

		while (ss >> buf){
			//the this that???????´¢
			if (buf.size() == 3 || buf.size() == 4){
				if (isthe(buf)){
					dif = (buf[0] - 't' + 26)%26;
					break;
				}
			}
		}

		for (int i = 0; i < s.size(); i++){
			if (s[i] >= 'a' && s[i] <= 'z') {
				s[i] -= dif;
				if (s[i] < 'a') s[i] += 26;
				if (s[i] > 'z') s[i] -= 26;
			}
		}

		cout << s << endl;
	}




	return 0;
}

C++: #include <bits/stdc++.h>
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define RFOR(i,a,b) for(int i=(b) - 1;i>=(a);i--)
#define REP(i,n) for(int i=0;i<(n);i++)
#define RREP(i,n) for(int i=n-1;i>=0;i--)

#define PB push_back
#define INF INT_MAX/3
#define ALL(a) (a).begin(),(a).end()
#define CLR(a) memset(a,0,sizeof(a))

typedef long long int ll;

using namespace std;

int main(){

    string s[] = {"this","the","that"};
    string in;
    while(true){
	getline(cin,in);
	if(cin.eof()) break;
	bool f = false;
	int d = 1;
	REP(i,30){

	    f = true;
	    REP(i,in.size()){
		if(in[i] == '.' || in[i] == ' ') continue;
		in[i]= (char)( 'a' + ( (int)(in[i] - 'a') + d) % 28);
	    }
	    vector<bool> flgs(3,false);
	    for(int i=0;i<in.size();i++){
		REP(j,3){
		    if(in.substr(i,s[j].size()) == s[j]) flgs[j] = true;
		}
	    }
	    if(flgs[0] && (flgs[1] || flgs[2])) break;
	}
	cout << in << endl;
    }

    return 0;
}

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;
      }
      unsigned f_the = str.find("the", 0);
      unsigned f_this = str.find("this", 0);
      unsigned f_that = str.find("that", 0);
      if((f_the != string::npos && (str[f_the - 1] == ' ' || str[f_the - 1] == '.' || str[f_the - 1] == '\n') && (str[f_the + 3] == ' ' || str[f_the + 3] == '.' || str[f_the + 3] == '\n')) || (f_this != string::npos && (str[f_this - 1] == ' ' || str[f_this - 1] == '.' || str[f_this - 1] == '\n') && (str[f_this + 4] == ' ' || str[f_this + 4] == '.' || str[f_this + 4] == '\n')) || (f_that != string::npos && (str[f_that - 1] == ' ' || str[f_that - 1] == '.' || str[f_that - 1] == '\n') && (str[f_that + 4] == ' ' || str[f_that + 4] == '.' || str[f_that + 4] == '\n')))
	cout << str << endl;	
    }
  }
}

C++: 
#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <cmath>
#include <stack>
#include <cctype>
#include <complex>
#include <vector>
#include <algorithm>

using namespace std;


bool solve(){
	
	string s;
	while(getline(cin,s)){
		string str[26];
		int num;
		for(int i=0;i<26;i++){
			str[i] = s;
			for(int j=0;j<str[i].size();j++){
				for(int k=0;k<i;k++){
					if(str[i][j]=='.' || str[i][j]==' '){
						continue;
					}
					if(str[i][j] == 'a'){
						str[i][j] == 'z';
					}
					str[i][j]--; 
				}
			}
			
			for(int j=0;j<str[i].size();j++){
				string str_temp, str_temp2;	
				if(j <= str[i].size()-3){
					str_temp  = str[i].substr(j,3);
				}
				if(j <= str[i].size()-4){
					str_temp2 = str[i].substr(j,4);
				}
				if(str_temp=="the" || str_temp2=="this" || str_temp2=="that"){
					num = i;
				}
			}
		}
		
		
		cout<< str[num]<< endl;
	}		
	
	return true;
}

int main(){
	cout.setf(ios::fixed);
	cout.precision(10);
	solve();

	return 0;
}