Go: package main

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

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 len(infos) == 0 {
			break
		}
		// 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 <iostream>
#include <string>

using namespace std;

string answer;

bool saiki( int advance, string target )
{
	for( int i = 0;i < target.size();i++ ){
		if( target[i] >= 'a' && target[i] <= 'z' ){target[i]+=advance; if( target[i] < 'a' || target[i] > 'z' ) return false;}
	}
	if( target.find( "the" ) != string::npos || target.find( "that" ) != string::npos || target.find( "this" ) != string::npos ){ answer = target;return true;  }
	else return saiki( advance, target );
}

int main(int argc, char const* argv[])
{
	string str;

	while( getline( cin, str ) ){
		if( str.find( "the" ) != string::npos || str.find( "that" ) != string::npos || str.find( "this" ) != string::npos ){ cout << str << endl;continue; }
		if(saiki( 1 ,str )){
			cout << answer << endl;
			continue;
		}
		if( saiki( -1 , str ) ){
			cout << answer << endl;
			continue;
		}
	}
	return 0;
}

C++: #include<iostream>
#include<cstring>
#include<algorithm>
#include<queue>
#include<cstdio>
#include<string>
using namespace std;
int main()
{
//    freopen("test.txt", "r", stdin);
 //   freopen("testout.txt", "w", stdout);
    string temp, ans;
    string guanjian[3] = { "this","the","that" };
    while (getline(cin, temp))
    {
        ans = temp;
        for (int i = 0; i <= 'z' - 'a'; i++)
        {
            //表示位移量。
            for (int j = 0; j<temp.size(); j++)
            {
                if (temp[j] >= 'a'&&temp[j] <= 'z')
                    ans[j] = (temp[j] - 'a' + i) % ('z' - 'a') + 'a';
                else ans[j]=temp[j];
            }
            if (ans.find(guanjian[0])!= string::npos ||
                    ans.find(guanjian[1]) != string::npos ||
                    ans.find(guanjian[2]) != string::npos)
            {
                cout << ans << endl;
                break;
            }
        }
    }
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define FOR(i, s, n) for(int i = s; i < (int)n; i++)
#define per(i, n) for(int i = n; i >= 0; i--)
#define ROF(i, s, n) for(int i = s; i >= (int)n; i--)
#define FORIT(i, A) for (auto i : A)
#define PRINT(x) cout << (x) << "\n"
#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define MP make_pair
#define EACH(i, n) for (__typeof((n).begin()) i = (n).begin(); i != (n).end(); ++i)
#define SZ(a) int((a).size())
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())
#define CLR(a) memset((a), 0 ,sizeof(a))
#define NCLR(a) memset((a), -1 ,sizeof(a))
#define dump(x) cout << #x << " = " << (x) << "\n";
#define debug(x) cout << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << "\n";
#define sq(n) (n) * (n)
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;
typedef vector<LL> VLL;
typedef vector<VLL> VVLL;
typedef unsigned int uint;
typedef unsigned long long ull;
typedef priority_queue<int> maxpq;
typedef priority_queue< int, vector<int>, greater<int> > minpq;
typedef complex<double> P;
static const double EPS = 1e-10;
static const double PI = acos( -1.0 );
static const int mod = 1000000007;
static const int INF = 1 << 30;
static const LL LL_INF = 1152921504606846976;
static const int dx[] = { -1, 0, 1, 0, 1, -1, 1, -1 };
static const int dy[] = { 0, -1, 0, 1, 1, 1, -1, -1 };

string str;

int main() {
	string str_copy;
	getline( cin, str );
	for ( int i = 1;; i++ ) {
		str_copy = str;
		for ( int j = 0; j < str_copy.size(); j++ ) {
			if ( str_copy[ j ] >= 'a' && str_copy[ j ] <= 'z' ) {
				str_copy[ j ] += i;
				str_copy[ j ] = ( ( str_copy[ j ] - 'a' ) % 26 ) + 'a';
			}
		}
		bool is_can = false;
		for ( int j = 0; j < str_copy.size() - 2; j++ ) {
			if ( str_copy.substr( j, 3 ) == "the" ) {
				is_can = true;
				break;
			}
		}
		for ( int j = 0; j < str_copy.size() - 3; j++ ) {
			if ( str_copy.substr( j, 4 ) == "that" || str_copy.substr( j, 4 ) == "this" ) {
				is_can = true;
				break;
			}
		}
		if ( is_can ) {
			break;
		}

	}
	printf( "%s\n", str_copy.c_str() );
	return 0;
}

C++: #include <iostream>
#include <algorithm>
#include<string>
#include<vector>
int main() {
	std::string s,a;
	std::getline (std::cin , s);
	int p = s[0] - 't';
	for (int i = 0; i < s.size(); ++i) {
		if (s[i] != ' ' &&s[i]!= '.') {
			if (s[i] - p < 'a') {
				a += 'z' - ('a' - (s[i] - p)-1);
			}
			else a += s[i] - p;
		}
		else a += s[i];
	}
	std::cout << a<< std::endl;
	return 0;
}

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

bool isSmallAlphabet(char& ch) {
  /* a ~ z(ascii) : 97 ~ 122 */
  if('a' <= ch && ch <= 'z') return true;
  else return false;
}

bool isHit(string& str) {
  if(str.find("the") != str.npos) return true;
  else if(str.find("this") != str.npos) return true;
  else if(str.find("that") != str.npos) return true;
  else return false;
}

/* ????????¶??????????§£??? */
void CaesarCipher(string _str) {
  
  /* parameter??????????????¢??????????????????????????????????????? */
  for(int parameter = 0; parameter < 26; ++parameter) {
    string str = _str;
    for(int i = 0; i < (int)str.length(); ++i) {
      
      /* ?°?????????¢??????????????????????????? */
      if(isSmallAlphabet(str[i])) {
        str[i] += parameter;
        /* ???????????????????°?????????§???????????£??????*/
        if(!isSmallAlphabet(str[i])) {
          str[i] -= 26;
        }
      }

    }

    /* Find "the" or "this" or "that" */
    if(isHit(str)) {
      cout << str << endl;
    }
  }
}

int main() {
  string str;
  while(getline(cin, str)) {
    CaesarCipher(str);
  }
  return 0;
}

C++: #include <iostream>

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 (s[j] >= 'a' && s[j] <= 'z') {
                    s[j] = (s[j] - 'a' + 1) % 26 + 'a';
                }
            }

            //cout << s << endl;

            if (s.find("the") != string::npos || s.find("this") != string::npos || s.find("that") != string::npos) {
                cout << s << endl;
                break;
            }
        }
    }

    return 0;
}