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<cstdio>
#include<cstring>
using namespace std;
char a[53]="abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz";
int main(){
    char str[81];
    for(int i=0;i<81;i++)str[i]=0;
    for(int i=0;i<80;i++){
        str[i]=getchar();
        if(str[i]==10)break;
    }
    int len=strlen(str);
    for(int i=0;i<26;i++){
        char cpy[81];
        strncpy(cpy,str,81);

        for(int j=0;j<len;j++){
            if(str[j]==' ' || str[j]=='.')continue;
            cpy[j]=a[cpy[j]-'a'+i];
        }
        bool f=false;
        for(int j=0;j<len-2;j++){
            if(!strncmp(cpy+j,"the",3))f=true;
            if(!strncmp(cpy+j,"this",4))f=true;
            if(!strncmp(cpy+j,"that",4))f=true;
        }
        if(f){
            cout<<cpy<<endl;
            break;
        }
    }
    return 0;


}

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

int search_number(const std::string &s)
{
    for (unsigned i = 0; i < s.size() - 3; ++i) {
        if (s[i] - s[i + 1] == 't' - 'h'
                && s[i + 1] - s[i + 2] == 'h' - 'i'
                && s[i + 2] - s[i + 3] == 'i' - 's')
            return s[i] - 't';
    }
    return 0;
}

int main()
{
    std::string s;
    while (getline(std::cin, s)) {
        int n = search_number(s);
        for (unsigned i = 0; i < s.size(); ++i) {
            if (s[i] != ' ' && s[i] != ',' && s[i] != '.') {
                s[i] -= n;
                if (s[i] < 'a') s[i] += 26;
                if (s[i] > 'z') s[i] -= 26;
            }
        }
        std::cout << s << std::endl;
    }
}

C++: #include <iostream>
#include <string>
#include <algorithm>
#include <cstdlib>
#include <vector>
using namespace std;
int main() {
	string str;
	string w[3] = { "the","this",  "that" };
	while (getline(cin, str)) {
		if (str == "")break;
		while (true) {
			if (str.find("this") == string::npos &&
				str.find("the") == string::npos &&
				str.find("that") == string::npos ) {

				for (char &c : str) {
					if (c != ' ' && c != '.') {
						c = (c - 'a' + 1) % 26 + 'a';
					}
				}

			}
			else {
				break;
			}
		}
		cout << str << endl;
	}
}

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 );
	}
	bool f = 0;
	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 )
			{
				f = 1;
			}
		}
		if( f )
		{
			for( auto P : data )
			{
				cout << P << endl;
			}
			return 0;
		}
	}
}

C++: /*AOJ 0017*/

#include<iostream>
#include<string>

using namespace std;

char shiftCaesar(char tmp){
	if(tmp>='a' && tmp<= 'y'){
		return tmp+1;
	}
	else if(tmp == 'z'){
		return 'a';
	}
	else{
		return tmp;
	}
}

int main(){
	char str[100];
	string tmp;

	while(cin.getline(str,100,'.')){

		for(;;){
			for(int i=0;str[i]!='\0';i++){
				str[i] = shiftCaesar(str[i]);
			}

			tmp = str;

			if( tmp.find("the") != -1 || tmp.find("this") != -1 || 
				tmp.find("that") != -1){
					break;
			}


		}

		cout<<tmp<<"."<<endl;

	}
	return 0;
}

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

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

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

using namespace std;
string buf;
bool found(){
    return buf.find("this",0) != string::npos ||
        buf.find("that",0) != string::npos ||
        buf.find("the",0) != string::npos;
}

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

int main(){
    while(getline(cin, buf)){
        while(!found()){
            for(int i=0; i<buf.size(); i++){
                if(isalpha(buf[i])) buf[i]++;
                if(buf[i] == 'z'+1) buf[i] = 'a';
            }
        }
        cout << buf << endl;
    }
}

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

	return 0;
}