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 <string>
using namespace std;

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

C++: #include <cmath>
#include <iostream>
#include <string>
#include <cstdlib>
#include <cstdio>
#include <algorithm>
#include <regex>

using namespace std;

string decode(string inp,int n){
    for(int i=0;i<inp.length();i++){
        if('a'<=inp[i]&&inp[i]<='z'){
            if(inp[i]-n<'a'){
                inp[i]='z'-(n-(inp[i]-'a')-1);

            }else{
                inp[i]=inp[i]-n;
            }
        }
    }
    return inp;
}
int main(){
    string input,decoded;
    regex pattern("(the)|(this)|(that)");
    while(getline(cin,input)){
        for(int i=0;i<26;i++){
            decoded=decode(input,i);
            if(regex_search(decoded.begin(),decoded.end(),pattern)){
                break;
            }
        }
        cout << decoded << endl;
    }
    return 0;
}

C++: #include <iostream>
#include <stdio.h>
#include <string.h>
#include <string>
#include <algorithm>
#include <vector>

using namespace std;

void q17() {
	vector<string> hints;
	hints.push_back("the");
	hints.push_back("this");
	hints.push_back("that");

	vector< vector<string> > shiftHints;
	for (int i = 0; i < 26; i++) {
		vector<string> iShiftHints;
		for (int j = 0; j < hints.size(); j++) {
			string tmp = "";
			for (int k = 0; k < hints[j].length(); k++) {
				tmp += ((hints[j][k] - 'a' + i) % 26) + 'a';
			}
			iShiftHints.push_back(tmp);
		}
		shiftHints.push_back(iShiftHints);
	}

	string str;
	for (; getline(cin, str);) {
		int s;
		bool flag = false;
		for (s = 0; s < 26; s++) {
			for (int i = 0; i < hints.size(); i++) {
				if (str.find(shiftHints[s][i]) != -1) {
					flag = true;
				}
			}
			if (flag) break;
		}

		string ans = "";
		for (int i = 0; i < str.length(); i++) {
			ans += isalpha(str[i]) ? (str[i] - 'a' - s + 26) % 26 + 'a' : str[i];
		}
		cout << ans << endl;
	}
}

int main() {
	q17();
	return 0;
}

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

using namespace std;

int main() { 
  string input_str;

  getline(cin, input_str);

  int shift = 1;
  while (1) {
    for (int str_i = 0; str_i < input_str.size(); str_i++)
      if (!isspace(input_str[str_i]))
        input_str[str_i] -= shift;
    if (input_str.find("the") > 0 ||
        input_str.find("this") > 0 ||
        input_str.find("that") > 0)
      break;
  }

  cout << input_str << endl;

  return 0;
}

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

bool NotMatch( const std::string& str )
{
	return str.find("the") == std::string::npos && str.find("this") == std::string::npos && str.find("that") == std::string::npos;
}

int main()
{
	std::string str;
	while( getline(std::cin,str) )
	{
		while( NotMatch(str) )
		{
			for( unsigned i=0; i<str.length(); ++i )
			{
				if( str[i]=='.' || str[i]==' ' || str[i]=='\n' )
				{
					continue;
				}

				if( str[i] == 'z' )
				{
					str[i] = 'a';
				}
				else
				{
					++str[i];
				}
			}
		}

		std::cout << str << '\n';
	}
}

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+3 <= str[i].size()){
					str_temp  = str[i].substr(j,3);
				}
				if(j+4 <= str[i].size()){
					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;
}

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



int main(int argc, const char * argv[])
{
    string word;
    while (getline(cin, word)) {
        int cnt = 0;
        for (char tmp2 = word[0]; tmp2 < 'z'; tmp2++) {
            if (tmp2 == 't') {
                break;
            }
            cnt++;
        }
        cnt = 0;
        for (char tmp2 = word[0]; tmp2 > 'a'; tmp2--) {
            if (tmp2 == 't') {
                break;
            }
            cnt--;
        }
        if (word[1] + cnt == 'h') {
            if (word[2] + cnt == 'e') {
                for (int i = 0; i < word.size(); i++) {
                    if (word[i] == '.') {
                
                    }
                    else if (word[i] != ' ') {
                        word[i] += cnt;
                    }
                }
            }
            if (word[2] + cnt == 'i' && word[3] + cnt == 's') {
                for (int i = 0; i < word.size(); i++) {
                    if (word[i] == '.') {
                        
                    }
                    else if (word[i] != ' ') {
                        word[i] += cnt;
                    }
                }
            }
            if (word[2] + cnt == 'a' && word[3] + cnt == 't') {
                for (int i = 0; i < word.size(); i++) {
                    if (word[i] == '.') {
                        
                    }
                    else if (word[i] != ' ') {
                        word[i] += cnt;
                    }
                }
            }
        }
        cout << word << endl;
    }

    
    return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i,a,n) for(int i=a;i<n;i++)
using namespace std;
 
int main() {
    string s;
    while(getline(cin,s)) {
        string t;
        rep(j,0,26) {
            t.clear();
            rep(i,0,s.length()) {
                if('a' <= s[i] && s[i] <= 'z') {
                    int val = (s[i] - 'a' + j) % 26;
                    t += ('a' + val);
                }
                else t += s[i];
            }
            if(t.find("this") != string::npos) break;
            else if(t.find("the") != string::npos) break;
            else if(t.find("that") != string::npos) break;
        }
        cout << t << endl;
    }
    return 0;
}