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 <iomanip>
#include <list>
#include <map>
#include <algorithm>
#include <stack>
#include <string>
#include <vector>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>

using namespace std;


int main(){
	string tmp;
	string key[] = {"the","this","that"};
	int alfabet = 26;
	bool clearFlag;
	while(getline(cin,tmp)){
		clearFlag = false;

		while(alfabet--){

			for(string::iterator it = tmp.begin(); it != tmp.end(); it++){
				if(*it >= 'a' && *it <= 'z'){
					(*it)++;
					if(*it >= 'z'){
						*it = 'a';
					}
				}
			}
			for(int j = 0; j < 3; j++){
				if(tmp.find(key[j]) != string::npos){
					cout << tmp << endl;
					clearFlag = true;
					break;
				}
			}

			if(clearFlag == true){
				break;
			}

		}

	}
	return 0;
}

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

using namespace std;

int main(int argc, char *argv[]) {
  string str, copy;
  int shif;
  vector<string> result;
  while (getline(cin, str)) {
    copy = str;
    shif = -1;
    while (true) {
      if (str.find(" this ") != string::npos ||
          str.find(" that ") != string::npos ||
          str.find(" the ") != string::npos)
        break;
      else
        for (string::iterator itr = str.begin();
             itr != str.end();
             itr++)
          if ('a' <= *itr && *itr <= 'z') {
            if (*itr == 'a')
              *itr = 'z';
            else
              *itr += shif;
          } else if (*itr != '.' && *itr != ' ' &&
                     *itr != '\n') {
            str = copy;
            shif = 1;
            break;
          }
    }
    result.push_back(str);
  }

  for (int i = 0; i < result.size(); i++)
    cout << result[i] << endl;
  return 0;
}

C++: #include<stdio.h>
#include<iostream>
#include<math.h>
#include<string>
using namespace std;
int main(){
	
	char s[1000];
	while(cin.getline(s,1000)){
		for(int i=0;s[i]!='\0';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'))||(s[i+1]-s[i+2]=='h'-'e')||((s[i+1]-s[i+2]=='h'-'a')&&(s[i+2]-s[i+3]=='a'-'t')))){
				for(int j=0;s[j]!='\0';j++){
					if((s[j]!=' ')&&(s[j]!='.')){
						if((s[j]+'t'-s[i]-'a')%24<0){
							putchar('z'-'a'+s[j]+'t'-s[i]+1);
						}else{
							putchar(s[j]+'t'-s[i]);
						}
					}else{
						putchar(s[j]);
					}
				}cout<<endl;
				break;
			}
		}
	}
	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] == ' ' || in[i] == '\n') continue;
		in[i]= (char)( 'a' + ( (int)(in[i] - 'a') + d) % 28);
	    }
	    vector<bool> flgs(3,false);
	    for(int i=0;i<in.size();i++){
		if(in[i] == ' '){
		    REP(j,3){
			if(in.substr(i+1,s[j].size()) == s[j] && in[i + s[j].size() + 1] == ' ') flgs[j] = true;
		    }
		}
	    }
	    if(flgs[0] || flgs[1] || flgs[2]) break;
	}
	cout << in << endl;
    }

    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[] = {"this","the","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;
	}
	REP(i,in.size()-1) cout << in[i] << " ";
	cout << in[in.size()-1] <<  endl;
    }

    return 0;
}

C++: #include<iostream>
#include<string>
#include<sstream>
#include<vector>
using namespace std;
#define REP(i, j) for(int i = 0; i < j; i++)
#define FOR(i, j, k) for(int i = j; i < k; i++)
const int N = 30;

bool isOK(string str){
    stringstream ss(str);
    vector<string> v;
    string tmp;
    while(ss >>tmp) v.push_back(tmp);
    REP(i, v.size()) if(v[i] == "the" || v[i] == "this" || v[i] == "that") return true;
    return false;
}

int main(){
    string str;
    while(getline(cin, str)){
        REP(z, N){
            REP(i, str.size()){
                if(!isalpha(str[i])) continue;
                str[i] = ++str[i] <= 'z'? str[i] : 'a';
            }
            if(isOK(str)){
                cout <<str <<endl;
                break;
            }
        }
    }
    return 0;
}