Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func incrementByte(b byte) byte {
	if b >= 97 && b < 122 {
		return b + 1
	} else if b == 122 {
		return 97
	}
	return b
}

func main() {
	scanner.Split(bufio.ScanLines)

	for {
		line := nextString()
		if len(line) == 0 {
			break
		}
		for i := 0; i <= 26; i++ {
			decoded := []byte{}
			for j := 0; j < len(line); j++ {
				decoded = append(decoded, incrementByte(line[j]))
			}
			line = string(decoded)
			if strings.Contains(line, "the") || strings.Contains(line, "this") || strings.Contains(line, "that") {
				fmt.Println(line)
				break
			}
		}
	}
}

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

using namespace std;

int main() {
    while(!cin.eof()) {
        string str;
        getline(cin, str);
        if(str == "") break;
        for(int shift = 0; shift < 26; ++shift) {
            if(str.find("the") != string::npos || str.find("this") != string::npos || str.find("that") != string::npos) break;
            for(int i = 0; i < str.size(); ++i) 
                if(islower(str[i]) && ++str[i] > 'z') str[i] = 'a';
        }
        cout << str << endl;
    }
    return 0;
}

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

int main() {
	string s;
	while (getline(cin,s)) {
		for (int i = 0;i < 26;++i) {
			for (char &c : s) {
				if (c != ' ' && c != '.') {
					++c;
					if (c > 'z') {
						c -= (char)26;
					} else if (c < 'a') {
						c += (char)26;
					}
				}
			}
			if (s.find("the") != string::npos || s.find("this") != string::npos || s.find("that") != string::npos) {
				cout << s << endl;
				break;
			}
		}
	}
}

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

int main() {

  string input = "";
  getline( cin, input );

  char c;
  for ( int i = 0; i < 26; i++ ) {

    string ans = "";
    for ( int j = 0; j < input.size(); j++ ) {

      c = input[j];
      if ( c >= 'a' && c <= 'z' ) {
	c = 'a' + ( c - 'a' + i )%26 ;
      }
      ans += c;

    }

    if ( ans.find( "the", 0 ) == string::npos && ans.find( "this", 0 ) == string::npos && ans.find( "that", 0 ) == string::npos ) continue;

    cout << ans << endl;

    break;

  }

  return 0;

}

C++: #include<iostream>
using namespace std;
int main(){
  char c,cans[29]={'X','Y','Z','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W'};
  int n;
  while(cin>>c){
    n = c - '@' - 1;
    cout << cans[n];
  }
  cout << endl;
  return 0;
}

C++: //include
//------------------------------------------
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <queue>
#include <iterator>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>

using namespace std;
using namespace string;

//conversion
//------------------------------------------
inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

//math
//-------------------------------------------
template<class T> inline T sqr(T x) {return x*x;}

//typedef
//------------------------------------------
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;

//container util
//------------------------------------------
#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())

//repetition
//------------------------------------------
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)

//constant
//--------------------------------------------
const double EPS = 1e-10;
const double PI  = acos(-1.0);

//clear memory
#define CLR(a) memset((a), 0 ,sizeof(a))

//debug
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

int gcd(int a, int b){
   int tmp;
   while(a%b==0){
      tmp=a%b;
      a=b;
      b=tmp;
   }
}

int lcm(int a,int b){
   return a*b/gcd(a,b);
}

bool prime_number(int n){
   if(n < 2){
      return false;
   }
   else if(n == 2){
      return true;
   }
   if(n % 2 == 0){
      return false;
   }
   for(int i=3;i<=n/i;i+=2){
      if(n % i == 0) return false;
      return true;
   }
}

int main(){
   string a;

   while(getline(cin,a)){
      while(a.find("the")==npos&&a.find("this")==npos&&str.find("that")==npos)
         REP(i,a.size()){
            if(a[i]=='z') a[i]=='a';
            else if(a[i]>=a&&a[i]<='z') a[i]++;
         }
      cout << a << endl;
   }
   return 0;
}

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

using namespace std;

int main()
{
  string stro, str;
  while(getline(cin, stro)){
    for(int i = 1; i < 26; i++){
      str = stro;
      for(int j = 0; j < stro.length(); j++){
	if(str[j] != ' ' && str[j] != '.' && str[j] != '\n')
	  if(str[j] + i > 'z')
	    str[j] += i - 26;
	  else
	    str[j] += i;
      }
      if((str.find("the ", 0) != string::npos && str[0] == 't') || (str.find("this ", 0) != string::npos && str[0] == 't') || (str.find("that ", 0) != string::npos && str[0] == 't') || str.find(" the.", 0) != string::npos || str.find(" this.", 0) != string::npos || str.find(" that.", 0) != string::npos || str.find(" the ", 0) != string::npos || str.find(" this ", 0) != string::npos || str.find(" that ", 0) != string::npos)
	  cout << str << endl;	
    }
  }
}

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

bool find(string str, string can) {
  string tmp_can = can;
  string tmp_str = str;
  int cnt = 0;
  for (int i = 0; i < tmp_str.length(); ++i) {
    if (string::npos != tmp_str.find(tmp_can, i)) {
      return true;
    }
  }
  return false;
}

int main() {
  string str;
  string candies[] = {"this", "the", "that"};
  while(getline(cin, str)) {
  for (int m = 1; m < 26; ++m) {
    for (int i = 0; i < str.length(); ++i) {
      if (str[i] == ' ') {
        continue;
      }
      if (str[i] == ',' || str[i] == '.') {
        str[i] = ' ';
        continue;
      }
      if ('a' <= str[i] && str[i] <= 'z') {
        int char_id = static_cast<int>(str[i]) - 97;
        int shifted = static_cast<int>(char_id + 1);
        str[i] = static_cast<char>(shifted % 26 + 97);
      }
    }
    for (int i = 0; i < sizeof(candies) / sizeof(candies[0]); ++i) {
      if (find(str, candies[i])) {
        cout << str << endl;
      }
    }
  }
  }
  return 0;
}

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

using namespace std;

string line;
int str_len;

bool is_finish() {
  for(int i=0; i<str_len-2; i++) {
    if(line[i] == 't') {
      if(line[i+1] == 'h') {
        if(line[i+2] == 'e') { return true; }
        else if(line[i+2] == 'i' && line[i+3] == 's') { return true; }
        else if(line[i+2] == 'a' && line[i+3] == 't') { return true; }
      }
    }
  }
  return false;
};


int main() {
  getline(cin, line);
  str_len = line.length();
  
  for(int j=0; j<26; j++) {
    if(is_finish()) { 
      cout << line << endl;
      break; 
    }

    for(int j=0; j<str_len; j++) {
      if('a' <= line[j] && line[j] < 'z') {
        line[j] += 1;
      }
      else if(line[j] == 'z') {
        line[j] = 'a';
      }
    }
  }
  return 0;
}