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>

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

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

using namespace std;
int main(){
	string str1;
	int i, j, n = 0;
	while(getline(cin, str1)){
		bool change = false;
		for(i = 0;i < 26;i++){
			for(j = 0;j < str1.size();j++){
				if(str1[j] != ' ' && str1[j] != '.'){
					if(str1[j] == 'a'){
						str1[j] == 'z';
					}
					else str1[j] -= 1;
				}
			}
			for(j = 0;j+3 < str1.size();j++){
				if(str1[j] == 't' && str1[j+1] == 'h'){
					if(str1[j+2] == 'e' || (str1[j+2] == 'i' && str1[j+3] == 's') || (str1[j+2] == 'a' && str1[j+3] == 't')){
						n = i + 1;
						change = true;
						break;
					}
				}
			}
			if(change) break;
		}	
		for(i = 0;i < str1.size();i++){
			cout << str1[i];
		}
		cout << 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[] = {"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) % 26);
	    }
	    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 <iostream>
#include <string>
using namespace std;
int main(){
      string s;
      while(getline(cin,s)){
            for(int i=0;i<25;i++){
                  if(s.find("the")!=-1||s.find("this")!=-1||s.find("that")!=-1)break;
                  else for(int j=0;j<s.size();j++)if(s[j]>='a'&&s[j]<='z')s[j]!='z'?s[j]++:s[j]='a';
            }
            cout<<s<<endl;
      }
}

C++: #include <cstdio>
#include <iostream>
#include <cstring>

using namespace std;

char data[26]={'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'};
char trans[100];
char mozi;
int position=0;
int zoom;
int first_check=0,first_position=0;
int now;
char result;

int main(){
	while(scanf("%c",&mozi)){

		if(first_check == 0)

		for(int i=0;i<26 && first_check == 0;i++){
			if(mozi == data[i]){
				first_position = i;
				zoom = first_position - 19;
				first_check = 1;
			}
		}




		if(mozi == ' ' || mozi == '.' || mozi == '\n'){
			if(mozi == ' ' || mozi == '.'){
				trans[position] = mozi;
				position++;
			}

			if(mozi == '\n'){
				trans[position] = '\n';
				cout << trans << endl;
				first_check = 0;
				position = 0;
				memset(trans,'\0',sizeof(trans));
			}
		}else{
			for(int i=0;i<26;i++){
				if(data[i] == mozi){
					now = i;
					break;
				}
			}

			trans[position] = data[now - zoom];
			position++;

		}
	}
}

C++: #include <bits/stdc++.h>
 
using namespace std;
 
#define FOR(i, j, k) for(int i = j; i < k; ++i)
#define rep(i, j) FOR(i, 0, j)
#define repr(i, j) for(int i = j; i >= 0; --i)
#define INF (1 << 30)
#define MOD 1e9 + 7
 
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> P;
 
int main() {
    string s;
    string ans;
    bool flag = false;
    int key = 1;
    while(getline(cin, s)){ans += s;}
    if(ans.size() <= 4) {
    	while(1) {
		    rep(i, ans.size()) {
		        if(97 <= ans[i] && ans[i] <= 122) {
		            int number = (ans[i] - 'a' + key) % 26;
		            ans[i] = 'a' + number; 
		        }
		    }
		    if(ans == "the" || ans == "this" || ans == "that") {
		    	cout << ans << endl;
		    	return 0;
		    }
		}
    }
    while(1) {
        rep(i, ans.size()) {
            if(97 <= ans[i] && ans[i] <= 122) {
                int number = (ans[i] - 'a' + key) % 26;
                ans[i] = 'a' + number;
            }
        }
        string tmp;
        rep(i, ans.size()) {
            if(97 <= ans[i] && ans[i] <= 122) tmp += ans[i];
            else if(ans[i] == ' ') {
                if(tmp == "this" || tmp == "the" || tmp == "that") flag = true;
                else tmp.erase(tmp.begin(), tmp.end());
            }
        }
        if(flag) break;
    }
    cout << ans << 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'<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;
}