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

C++: #include <bits/stdc++.h>
using namespace std;
#define REP(i,n) for(int i=0; i<(n); i++)
#define REP2(i,x,n) for(int i=x; i<(n); i++) 
#define ALL(n) begin(n),end(n)
struct cww{cww(){ios::sync_with_stdio(false);cin.tie(0);}}star;
int main()
{
	string S;
	while( getline( cin, S ) )
	{
		while( true )
		{
			REP( i, (int)S.size() )
			{
				if( S[ i ] != ' ' && S[ i ] != '.' )
				{
					if( S[ i ] == 'z' )
					{
						S[ i ] = 'a';
						continue;
					}
					S[ i ]++;
				}
			}
			if( S.find( "the" ) != string::npos || S.find( "this" ) != string::npos || S.find( "that" ) != string::npos )
			{
				break;
			}
		}
		cout << S << endl;
	}
	return 0;
}

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

int main(){
    string str;
    
    while(getline(cin,str)){
        int flg = 0;
        
        while(true){
            for(int i = 0 ; i < str.length() ; i++){
                string key1 = str.substr(i,3),key2 = str.substr(i,4);
                if(key1 == "the" || key2 == "that" || key2 == "this") flg = 1;
            }
            
            if(flg) goto end;
            else{
                for(int j = 0 ; j < str.length() ; j++){
                    if('a' <= str[j] && str[j] <= 'z'){
                        str[j] -= 'a' - 'A';
                        str[j] = (char)('A'+(str[j]-'A'+26+1)%26);
                        str[j] += 'a' - 'A';
                    }
                    else continue;
                }
            }
        }
    }
    end:
    cout << str << endl;
    
    return 0;
}

C++: #include <iostream>
#include <string.h>
#include <string>
#include <stdio.h>
using namespace std;
int main() {
	char st[80];
	string w[3]={"the","this","that"};
	int wn[3]={3,4,4},k,i,j,s,f,z;
	while(true) {
    k=0; z=0;
	scanf("%[^0]",st);
	z=strlen(st);
	while(k<z) {
		for (i=0;i<3;i++) {
			s=0; f=0;
			if (z<k+wn[i]) break;
			for (j=0;j<wn[i]-1;j++) if ((w[i][j]-w[i][j+1])==(st[k+j]-st[k+j+1])) s++;
			if (s==wn[i]-1 && (st[k+wn[i]]<'a' || st[k+wn[i]]>'z' ))  { f=1; i=5;}
		}
		if (f==1) break;
		for (k;st[k]>='a' && st[k]<='z';k++);
		k++;
		}
	if (f==0) cout << st; else {
	for (i=0;i<z;i++) if ((st[i]>='a' && st[i]<='z')) cout << (char)(st[i]-(st[k]-'t')) ; else cout << st[i];
	  }	
	}
    return 0;
	}

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


int main()
{
	string str;
	int len;
	int i,j;
	while(1) {
		getline(cin,str);
		if(cin.eof())
			break;

		len = str.length();
		for(i = 0; i < 26; i++ ) {
			for ( j = 0; j < len; j++ ) {
				if ( 'a' <= str[j] && str[j] <= 'z') {
					str[j]++;
					if ( str[j] > 'z')
						str[j] = 'a';
				}
			}
			if( str.find("the") != string::npos || str.find("this") != string::npos
			|| str.find("that") != string::npos ) {
				cout << str << endl;
				break;
			}
		}
	}

	return 0;
}

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

int main(){
  string word;
  string com[3]={"the","this","that"};
  int cou=0;

  while(1){
    //bool flag = false;
    getline(cin,word);
    if(cin.eof()){
      break;
    }
    while(1){
      bool flag = false;
      for(int i=0;i<word.size();i++){
	if(word[i] == 'z'){
	  word[i] = 'a';
	}
	else if(word[i] >= 'a' && word[i] <= 'z'){
	  word[i]++;
	}
      }
      for(int i=0;i<3;i++){
	int index = word.find(com[i],0);
	if(index != string::npos){
	  cout << word << endl;
	  flag = true;
	  break;
	}
      }
      if(flag == true) break;
    }
  }
}

C++: #include <bits/stdc++.h>

using namespace std;

int main() {
	string str;
	while (getline(cin, str)) {
		int cnt = 0;
		for (int i = 0; i < 26; ++i) {
			for (int j = 0; j < (int)str.size(); ++j) {
				if (str[j] >= 'a' && str[j] <= 'z') {
					str[j] = (str[j] - 'a' + 1) % 26 + 'a';
				}
			}
			cnt++;
			if (str.find("the") != string::npos || str.find("this") != string::npos || str.find("that") != string::npos) break;
		}
		for (int i = 0; i < 26; ++i) {
			for (int j = 0; j < (int)str.size(); ++j) {
				if (str[j] >= 'a' && str[j] <= 'z') {
					str[j] = (str[j] - 'a' + cnt) % 26 + 'a';
				}
			}
		}
		cout << str << endl;
	}
}

C++: #include<bits/stdc++.h>
using namespace std;
int main()
{
    string str;
    while(getline(cin,str)){
            while(1){
                if(str.find("the")!=-1||str.find("that")!=-1||str.find("this")!=-1)break;
                for(int i=0;i<str.size();i++){
                    if(str[i]=='.'||str[i]==' '){}
                    else str[i]--;
                }
            }
            cout<<str<<endl;
    }

}