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 <string>
using namespace std;

int main()
{
	string s;
	int n;
	while (getline(cin, s))
	{
		n = s.size();
		for (int i = 1; i < 27; i++)
		{
			for (int j = 0; j < n; j++)
			{
				if (s[j] == ' ' || s[j] == '.')
				{
					continue;
				}
				if (s[j] == 'z')
				{
					s[j] = 'a';
					continue;
				}
				s[j] ++;

			}
			

			bool ba = s.find("the") != string::npos;
			bool bb = s.find("this") != string::npos;
			bool bc = s.find("that") != string::npos;
			if (ba || bb || bc)
			{
				cout << s << endl;
			}
			
		}
	}

	return 0;
}

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

int main(void){
    string str;
    
    while(getline(cin,str)){
  
        for(int i = 0 ; i < str.size() ; i++){
            if('a' <= str[i] && str[i] <= 'z') cout << (char)('a'+(str[i]-'a'+26-4)%26);
            else cout << str[i];
        }
        puts("");
    }
    
    return 0;
}

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

struct words {
	char str[82] ;
} w[82] ;

int p ;
int key ;
char c ;

bool isalpha ( char s ) ;

int main ( )
{
	p = 0 ;
	key = 9999 ;
	while ( scanf ( "%s" , w[p].str ) == 1 ) {
		c = getchar ( ) ;
		if ( strlen ( w[p].str ) == 4 && key == 9999 ) {
			if ( w[p].str[0] - w[p].str[1] == 't' - 'h' && w[p].str[1] - w[p].str[2] == 'h' - 'i' && w[p].str[2] - w[p].str[3] == 'i' - 's' ) {
				key = 't' - w[p].str[0] ;
			}
			else if ( w[p].str[0] - w[p].str[1] == 't' - 'h' && w[p].str[1] - w[p].str[2] == 'h' - 'a' && w[p].str[2] - w[p].str[3] == 'a' - 't' ) {
				key = 't' - w[p].str[0] ;
			}
		}
		else if ( strlen ( w[p].str ) == 3 && key == 9999 ) {
			if ( w[p].str[0] - w[p].str[1] == 't' - 'h' && w[p].str[1] - w[p].str[2] == 'h' - 'e' ) {
				key = 't' - w[p].str[0] ;
			}
		}
		p++ ;
		if ( c == '\n' ) {
			for ( int i = 0 ; i < p ; i++ ) {
				for ( int j = 0 ; w[i].str[j] ; j++ ) {
					if ( isalpha ( w[i].str[j] ) ) {
						w[i].str[j] += key ;
						if ( w[i].str[j] > 'z' ) {
							w[i].str[j] -= 26 ;
						}
						else if ( w[i].str[j] < 'a' ) {
							w[i].str[j] += 26 ;
						}
					}
				}
				if ( i != 0 ) {
					printf ( " " ) ;
				}
				printf ( "%s" , w[i].str ) ;
			}
			printf ( "\n" ) ;
			p = 0 ;
			key = 9999 ;
		}
	}
	return 0 ;
}

bool isalpha ( char s )
{
	return ( s >= 'a' && s <= 'z' ) ;
}

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

using namespace std;

int main() {
    string input;
    const int alph_lim = 26;

    while (getline(cin, input, '\n')) {
        for (int i = 0; i < alph_lim; i++) {
            for (int j = 0; j < input.size(); j++){
                if(islower(input[j])) {
                    input[j]++;
                    if (input[j] > 'z') {
                        input[j] -= alph_lim;
                    }
                }
            }

            if (input.find("this") != string::npos
                || input.find("that") != string::npos
                || input.find("ths") != string::npos) {

                cout << input << endl;
                break;
            }
        }
    }
    return 0;
}

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

int main ()
{
    int i;
    char str[1000];
    fgets(str, 1000, stdin);

    for (i = 0; i < strlen (str); i++){
        if (str[i] >= 'a' && str[i] <= 'z'){
            str[i] = str[i] - 4;
        }
    }
    printf("%s\n", str);
    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[] = {"the","this","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 str;
  while(getline(cin,str)){
    while(str.find("the")==-1&&
	  str.find("this")==-1&&
	  str.find("that")==-1){
      int i;
      for(i=0;i<str.size();i++){
	if('a'<=str[i]&&str[i]<'z') str[i]++;
	else if(str[i]=='z') str[i]='a';
      }
    }
    cout << str << endl;
  }
  return 0;
}

C++: #include<iostream>
#include<string>
using namespace std;
main(){
	string str;
	int tmp,b;
	while(getline(cin,str)){
		tmp='t'-str[0];
		for(int i=0;i<str.size();++i){
			if(str[i]>='a' && str[i]<='z'){
				if(str[i]>='m')str[i]-=26;
				str[i]+=tmp;
				if(str[i]<'a')str[i]+=26;
				else if(str[i]>'z')str[i]-=26;
			}
		}
		/*string str2="";
		for(int i=0;i<=4;++i){
			if(str[i]>='a' && str[i]<='z')str2+=str[i];
			else break;
		}*/
		//if(str2=="this" || str2=="the" || str2=="that")
		cout<<str<<endl;
	}
}

C++: #include<cstdio>
#include<algorithm>
#include<vector>
#include<string>
#include<iostream>
#include<queue>
#include<map>
#include<set>
#include<complex>
#include<stack>
#include<cmath>

using namespace std;

#define reps(i,f,n) for(int i=f;i<int(n);i++)
#define rep(i,n) reps(i,0,n)


#define X real()
#define Y imag()
typedef complex<double> P;

const double EPS = 0.1;

int main(){
	
	while(1){
		string a;
		getline(cin,a);
		
		if(cin.eof())break;
		
		rep(i,26){
			string s;
			rep(j,a.size()){
				if(a[j]<'a' || a[j]>'z')s+=a[j];
				else s+=(a[j]-'a'+i)%26+'a';
			}
			if(s.find("this")!=-1 || s.find("the")!=-1 || s.find("that")!=-1){
				cout<<s<<endl;
				goto A;
			}
		}
		A:;
	}
}