Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

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

func incrementByte(b byte) byte {
	if b >= 97 && b < 122 {
		return b + 1
	} else if b == 122 {
		return 97
	}
	return b
}

func main() {
	scanner.Split(bufio.ScanLines)

	for {
		line := nextString()
		if len(line) == 0 {
			break
		}
		for i := 0; i <= 26; i++ {
			decoded := []byte{}
			for j := 0; j < len(line); j++ {
				decoded = append(decoded, incrementByte(line[j]))
			}
			line = string(decoded)
			if strings.Contains(line, "the") || strings.Contains(line, "this") || strings.Contains(line, "that") {
				fmt.Println(line)
				break
			}
		}
	}
}

C++: #ifndef _GLIBCXX_NO_ASSERT
#include <cassert>
#endif
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>

#ifdef __GXX_EXPERIMENTAL_CXX0X__
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>
#endif

#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>

#ifdef __GXX_EXPERIMENTAL_CXX0X__
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#endif

using namespace std;


int main ()
{
	string str , str2;
	while( getline ( cin , str2 ) )
	{
		str += str2;
	}
	for( size_t i = 0; i < 26; i++ )
	{
		for( auto &x : str )
		{
			if( x <= 'z'&&'a' <= x )
			{
				x -= 'a';
				x += 1;
				x %= 26;
				x += 'a';
			}
		}
		if( str.find ( "the" ) != string::npos || str.find ( "this" ) != string::npos || str.find ( "that" ) != string::npos )
		{
			cout << str << endl;
			return 0;
		}
	}
}

C++: #include <iostream>
#include <sstream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>
#include <string>
#include <vector>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <algorithm>
#include <functional>

using namespace std;

int main()
{
	string str;

	while ( getline( cin, str ) )
	{
		for ( unsigned int i = 0; i < 26; i++ )
		{
			for ( unsigned int i = 0; i < str.length(); i++ )
			{
				if ( 'a' <= str[i] && str[i] <= 'z' )
				{
					str[i]++;
					if ( 'z' <= str[i] )
					{
						str[i] -= 'z' - 'a';
					}
				}
			}

			if ( str.find("the") != string::npos || str.find("this") != string::npos || str.find("that") != string::npos )
			{
				cout << str << endl;
				return 0;
			}
		}
	}

	return 0;
}

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

int main(){
	int i, j;
	string input, s;
	while(getline(cin, input)){
		for (i = 0; i < 26; i++) {
			s = input;
			for(j = 0; j < s.length(); j++){
				if(s[j] != '.' && s[j] != ' '){
					s[j] = s[j] - i;
				}
			}
			if(s.find("the")!=string::npos || s.find("this")!=string::npos || s.find("that")!=string::npos){
				cout << s << endl;
				break;
			}
		}
	}
	return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <vector>
using namespace std;
typedef pair<int,char*> str;

int main(void){
	char s[81];
	vector<str> v;
	const char* cmp1="that";
	const char* cmp2="this";
	const char* cmp3="the";
	bool is_found=false;
	int pos=0,end_pos,diff;
	char c;

	scanf("%[^\n]",s);
	for(int i=0;i<81;i++){
		if(s[i]==' ' || s[i]=='.'){
			s[i]='\0';
			v.push_back(str(i-1-pos,s+pos));
			pos=i+1;
		}else if(s[i]=='\0'){
			end_pos=i;
			break;
		}
	}

	for(int i=0;i<v.size();i++){
		is_found=false;

		diff=1000;
		if(v[i].first==4){
			for(int j=0;j<4;j++){
				if(diff==1000){
					diff=v[i].second[j]-cmp1[j];
				}else if(diff!=v[i].second[j]-cmp1[j]){
					is_found=true;
					break;
				}
			}

			if(!is_found) break;

			diff=1000;
			for(int j=0;j<4 && !is_found;j++){
				if(diff==1000){
					diff=v[i].second[j]-cmp2[j];
				}else if(diff!=v[i].second[j]-cmp2[j]){
					is_found=true;
					break;
				}
			}

			if(!is_found) break;
		}else if(v[i].first==3){
			diff=1000;
			for(int j=0;j<3;j++){
				if(diff==1000){
					diff=v[i].second[j]-cmp2[j];
				}else if(diff!=v[i].second[j]-cmp2[j]){
					is_found=true;
					break;
				}
			}
			if(!is_found) break;
		}
	}
	
	for(int i=0;i<end_pos;i++){
		if(s[i]=='\0'){
			if(i==end_pos-1){
				s[i]='.';
			}else{
				s[i]=' ';
			}
		}else{
			s[i]-=diff;
		}
	}

	printf("%s\n",s);


	return 0;
}

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

int main(){

	string code;

	while( getline(cin, code) ){

		for( int j=0;j<25;j++ ){
			for( int i=0;i<code.size();i++ ){
				if( code[i] >= 'a' && code[i] <= 'z' ){
					code[i] += 1;
					if(code[i]=='z'+1)code[i]='a';
				}
			}
			if(code.find("the ") != -1 || code.find("this") != -1 || code.find("that") != -1)
				break;		
		}
		cout << code << endl;
	}
	return 0;

}

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

int main()
{
	string str;
	while(getline(cin,str)){
		int l,m;
		l = static_cast<int>(str[0] - 't');
		m = static_cast<int>(str[1] - 'h');
		char a = static_cast<char>(static_cast<int>(str[2])-l);
		char b = static_cast<char>(static_cast<int>(str[3])-l);
		if(l == m && ( a=='e' || (a=='i'&&b=='s') || (a=='a'&& b=='t'))){
			for(unsigned i=0;i<str.size();i++){
				if(islower(str[i])){
					char c = static_cast<char>(static_cast<int>(str[i])-l);
					if(c<'a')
						c += 26;
					else if(c>'z')
						c-=26;
					cout << c;
				}else{
					cout << str[i];
				}
			}
			cout << endl;
		}
	}
	return 0;
}

C++: // #define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <algorithm>
#include <vector>
#include <cstdlib>
#include <cstdio>
#include <string>
#include <cmath>
using namespace std;

string nextChar(string in){
	for (int i = 0; i < in.length(); i++){
		// アルファベットなら
		if (in[i] >= 97 && in[i] <= 122){
			// 次に進める
			in[i]++;
			if (in[i] == 123)	in[i] = 97;
		}
	}
	return in;
}

int main(){
	string in;
	while (getline(cin, in)){
		while (1){
			in = nextChar(in);
			if (in.find("the") != string::npos || 
				in.find("this") != string::npos || 
				in.find("that") != string::npos){
				cout << in << endl;
				break;
			}
		}
	}
	return 0;
}

C++: #include <iostream>
#include <string>
using namespace std;
int main( void )
{
	// ³ê½f[^É the, this, that Ì¢¸ê©ªÜÜêéÈçÎ
	// »êðoÍµÄI¹·éÆ¢¤àÌÅµå¤B

	string keys[3] = { "the", "this", "that" };
	string input;
	while ( cin.eof() == false )
	{
		getline( cin, input );
		for ( int i = 0; i <= 26; i++ )
		{
			for ( string::iterator it = input.begin(); it != input.end(); it++ )
			{
				if ( *it == '\n' ) it = input.erase( it );
				if ( 'a' <= *it && *it <= 'z' )
				{
					(*it)++;
					if ( *it > 'z' ) *it = 'a';
				}
			}
			bool not_found = true;
			for ( int j = 0; not_found && j < 3; j++ )
			{
				if ( input.find( keys[j] ) != string::npos ) not_found = false;
			}
			if ( not_found == false )
			{
				cout << input << endl;
				break;
			}
		}
	}

	return 0;
}