Go: package main

import (
	"bufio"
	"os"
	"strings"
	"fmt"
	"reflect"
)

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 reflect.DeepEqual(infos, []string{}) {
			break
		}
		fmt.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 <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++){
		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>
#include<vector>
using namespace std;

int main(void){
  string s;
  string a[3] = {"this","the","that"};
  getline(cin,s);
  vector<string> ss;
  string n = "";
  s += " ";
  for(int i = 0  ; i < s.size() ; i ++){
    if(s[i] == ' '){
      ss.push_back(n);
      n = "";
    }else{
      n += s[i];
    }
  }
  bool ans = true;
  while(ans){
    for(int i = 0 ; i < ss.size() ; i ++){
      for(int j = 0 ; j < ss[i].size() ; j ++){
	ss[i][j] ++;
      }
      //cout<<ss[i]<<" ";
      for(int j = 0 ; j < 3 ; j ++){
	if(ss[i] == a[j]) ans = false;
	break;
      }
    }
  }
  for(int i = 0 ; i < ss.size() ; i ++){
    cout<<ss[i]<<" "; 
  }
  cout<<endl;
}

C++: #include <iostream>
#include <cstring>
#include <cstdlib>
#include <algorithm>
#include <vector>
#include <cstdio>
#include <map>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,b) FOR(i,0,b)
#define PB push_back
#define MP make_pair
char rec(char x,int s){
  if(x-s<'a')return x-s+26;
  if(x-s>'z')return x-s-26;
  return x-s;
}
int main(){
  string s[80];
  int k=0,l=0;
  while(cin>>s[k]){
    int y=s[k][0]-'t';
    if(s[k].size()==3){
      if(rec(s[k][1],y)=='h'&&rec(s[k][2],y)=='e')l=y;
    }
    if(s[k].size()==4){
      if(rec(s[k][1],y)=='h'&&rec(s[k][2],y)=='a'&&rec(s[k][3],y)=='t')l=y;
      else if(rec(s[k][1],y)=='h'&&rec(s[k][2],y)=='i'&&rec(s[k][3],y)=='s')l=y;
    }
    k++;
  }
  for(int i=0;i<k;i++){
    for(int j=0;j<s[i].size();j++){
      if(s[i][j]=='.')cout<<'.';
      else cout<<rec(s[i][j],l);
    }
    if(i==k-1)cout<<endl;
    else cout<<" ";
  }
}

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

int main() {
	string str; 
	while (getline(cin, str)) {
		for (int i = 0; i < 26; i++) {
			for (auto &itr : str) if (isalpha(itr)) itr = (itr - 'a' + 1) % 26 + 'a';
			if (str.find("the") != -1) { cout << str << endl; break; }
			if (str.find("this") != -1) { cout << str << endl; break; }
			if (str.find("that") != -1) { cout << str << endl; break; }
		}
	}
	return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<cmath>
#include<vector>
#include<list>
#include<set>
#include<map>
#include<stack>
#include<queue>
#include<string>
#include<utility>
#include<algorithm>
#include<functional>
#include<deque>
#include<string.h>
#include<ctype.h>
#include<time.h>
#include<stdlib.h>
using namespace std;

char c[80], word[40][10];
int p = 0, q = 0;

bool search_th(){
  for (int i = 0; i <= p; i++){
    if (word[i][0] == 't' && word[i][1] == 'h'){
      if (word[i][2] == 'e' || (word[i][2] == 'i' && word[i][3] == 's') || (word[i][2] == 'a' && word[i][3] == 't')){
        return true;
      }
    }
  }
  return false;
}

void split_words(){
  for (int i = 0; i < 40; i++){
    for (int j = 0; j < 10; j++){
      word[i][j] = '\0';
    }
  }
  for (int i = 0; i < strlen(c); i++){
    if (c[i] >= 'a' && c[i] <= 'z'){
      word[p][q++] = c[i];
    } else {
      p++;
      word[p++][0] = c[i];
      q = 0;
    }
  }
  for (int i = 0; i <= p; i++){
    printf("word[%d]:%s\n", i, word[i]);
  }
}

int main(){
  while (cin.getline(c, sizeof(c))){
    p = 0;  q = 0;
    split_words();
    while (1){
      if (search_th() == true){
        for (int i = 0; i <= p; i++){
          cout << word[i];
        }
        puts("");  break;
      } else {
        for (int i = 0; i <= p; i++){
          for (int j = 0; j < strlen(word[i]); j++){
            if (word[i][j] >= 'a' && word[i][j] <= 'y') word[i][j]++;
            if (word[i][j] == 'z')                      word[i][j] = 'a';
          }
        }
      }
    }
    for (int i = 0; i < 80; i++){
      c[i] = '\0';
    }
  }
  return 0;
}

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

bool howMuchWords(string s, string key){
  string::size_type index = s.find(key);
  if(index == string::npos){
    return false;
  }else{
    //???????????£???.
    return true;
  }
}
    

int main(){
  string s;
  getline(cin ,s);
  int cnt=0;

  while(true){
    if(howMuchWords(s, "that") || howMuchWords(s, "this") || howMuchWords(s, "the")){
      // cout << cnt << ": ";
      cout << s << endl;
      break;
    }

    for(int i=0;i<s.length();i++){
      if(s[i] > 'a' && s[i] < 'z'){
	s[i] -= 'a';
	s[i] -= 1;
	if(s[i] < 0){
	  s[i] += 'A' - 'a';
	}
	s[i] += 'a';
      }
    }
    
  }
}

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

using namespace std;

string dict = "abcdefghijklmnopqrstuvxwyz";

string decode(string s, int v) {
    string ans = s;
    for(int i = 0; i < (int) s.size(); i++) {
        if(s[i] >= 'a' && s[i] <= 'z') {
            ans[i] =  dict[((s[i] + v) % 26)];
        }
    }
    return ans;
}

int main() {
    string s;

    while(getline(cin, s)) {
        for(int i = 1; ; i++) {
            string tmp = decode(s, i);
            if(tmp.find("this") != string::npos && tmp.find("the") != string::npos && tmp.find("that") != string::npos) {
                cout << tmp << endl;
                break;
            }
         }
    }
    return 0;
}