Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

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 scanner.Scan() {
		infos := strings.Split(scanner.Text(), " ")
		plain := make([]string, len(infos))
		// 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<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<cassert>
#include<iostream>
#include<sstream>
#include<string>
#include<vector>
#include<queue>
#include<set>
#include<map>
#include<utility>
#include<numeric>
#include<algorithm>
#include<bitset>
#include<complex>

using namespace std;

typedef long long Int;
typedef vector<int> vint;
typedef pair<int,int> pint;
#define mp make_pair

template<class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cout << *i << " "; cout << endl; }
template<class T> void chmin(T &t, T f) { if (t > f) t = f; }
template<class T> void chmax(T &t, T f) { if (t < f) t = f; }
int in() { int x; scanf("%d", &x); return x; }

int main() {
	string str;
	char chr[100];
	for(;gets(chr);){
		str=chr;
		int len=str.size();
		int i,c;
		for(c=1;c<=26;c++){
			for(i=0;i<len;i++){
				if('a'<=str[i]&&str[i]<='z'){
					str[i]++;
					if(str[i]>'z')str[i]='a';
				}
			}
			//cout<<str<<endl;
			if(str.find("the")!=string::npos||str.find("this")!=string::npos||str.find("that")!=string::npos){
				cout<<str<<endl;
				break;
			}
		}
	}
	return 0;
}

C++: #include <iostream>
using namespace std;
#include <stdio.h>
#include <string.h>
#include <string>
#include <algorithm>
#include <vector>

void q17() {
	vector<string> hints;
	hints.push_back("the");
	hints.push_back("this");
	hints.push_back("that");

	vector<vector<string>> shiftHints;
	for (int i = 0; i < 26; i++) {
		vector<string> iShiftHints;
		for (int j = 0; j < hints.size(); j++) {
			string tmp = "";
			for (int k = 0; k < hints[j].length(); k++) {
				char z = ((hints[j][k] - 'a' + i) % 26) + 'a';
				tmp += ((hints[j][k] - 'a' + i) % 26) + 'a';
			}
			iShiftHints.push_back(tmp);
		}
		shiftHints.push_back(iShiftHints);
	}

	string str;
	for (; getline(cin, str);) {
		int s;
		bool flag = false;
		for (s = 0; s < 26; s++) {
			for (int i = 0; i < hints.size(); i++) {
				if (str.find(shiftHints[s][i]) != -1) {
					flag = true;
				}
			}
			if (flag) break;
		}

		string ans = "";
		for (int i = 0; i < str.length(); i++) {
			if ('a' <= str[i] && str[i]<= 'z') {
				ans += (str[i] - 'a' - s) % 26 + 'a';
			}
			else {
				ans += str[i];
			}
		}
		cout << ans << endl;
	}
}

int main() {
	q17();
	return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<string>
using namespace std;
int main(){
  string s;
  int pl=0;
  while(getline(cin,s)){
  for(int i =-30;i<30;i++){
    for(int j = 0; j < s.size()-3; j++){
      if(s[j]+i=='t' &&s[j+1]+i == 'h' && s[j+2]+i == 'e'&& s[j+3]==' '){
	pl = i;
	break;
      }
      if(j==s.size()-1) break;
      if(s[j]+i=='t' &&s[j+1]+i == 'h' && s[j+2]+i == 'a' && s[j+3]+i=='t' && s[j+4]==' '){
	pl = i;
	break;
      }
      if(s[j]+i=='t' &&s[j+1]+i == 'h' && s[j+2]+i == 'i' && s[j+3]+i=='s' && s[j+4]==' '){
	pl = i;
	break;
      }
    }
    if(pl!=0) break;
  }
  for(int i=0;i <s.size();i++){
    if(s[i]<='z' && s[i]>='a') s[i] += pl;
  }
  cout<<s<<endl;
  pl=0;
  }
}

C++: #include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <cmath>
#define INF 1000000000

using namespace std;

// the this that

vector<string> split(string str, string delim) {
  vector<string> res;
  int cutAt;
  while ((cutAt = str.find_first_of(delim))!=str.npos) {
    if (cutAt > 0) {
      res.push_back(str.substr(0,cutAt));
    }
    str = str.substr(cutAt+1);
    if (str.length() > 0) {
      res.push_back(str);
    }
  }
  return res;
}

int main() {
  string str;
  while (getline(cin, str)) {
    vector<string> strs=split(str," ");
    int key=0;
    for (int i=0; i<strs.size(); i++) {
      while (strs[i].find(".")!=string::npos) {
	strs[i].erase(strs[i].find("."));
      }
      if (strs[i].length()==3&&strs[i][0]-'t'==strs[i][1]-'h'&&strs[i][1]-'h'==strs[i][2]-'e') {
	key = strs[i][0]-'t';
	break;
      } else if (strs[i].length()==4) {
	if (strs[i][0]-'t'==strs[i][1]-'h'&&strs[i][1]-'h'==strs[i][2]-'a'&&strs[i][2]-'a'==strs[i][3]-'t') {
	  key = strs[i][0]-'t';
	  break;
	}
	if (strs[i][0]-'t'==strs[i][1]-'h'&&strs[i][1]-'h'==strs[i][2]-'i'&&strs[i][2]-'i'==strs[i][3]-'s') {
	  key = strs[i][0]-'t';
	  break;
	}
      }
    }
    for (int i=0; i<str.length(); i++) {
      if (isalpha(str[i])) {
	str[i]-=key;
      }
    }
    cout<<str<<endl;
  }
}

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++){
      s[i] = s[i] + 1;
    }
    
  }
}

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

int main(){

   string str;
   bool ans=false;
   
   
   while(getline(cin,str)){
   ans=false;
   
   string::iterator ite=str.begin();
   
   while(1){
      //cout << str.find("the");
      if(str.find("the")<=str.size()) ans=true;
      else if(str.find("this")<=str.size()) ans=true;
      else if(str.find("that")<=str.size()) ans=true;
      if(ans) break;
      for(int i=0;i<str.size();i++){
         if(*(ite+i)>='A'&&*(ite+i)<='z') *(ite+i)-=1;
      }
   }
   cout << str << endl;
   }
   return 0;
}

C++: #include <cstdio>
#include <string.h>

using namespace std;

int main()
{
	char in[81];
	char tht[3][10] = {"the","this","that"};
	int len;
	bool end;

	while(gets(in)){
		len = strlen(in);
		end = false;
		for(int i = 0; i < 26; i++){
			for(int j = 0; j < len; j++){
				if(in[j] >= 'a' && in[j] <= 'z'){
					if(in[j] == 'z'){
						in[j] = 'a';
					}
					else{
						in[j]++;
					}
				}
			}
			for(int c = 0; c < 3; c++){
				if(strstr(in,tht[c]) != NULL){
					printf("%s\n",in);
					end = true;
					break;
				}
			}
			
			if(end){
				break;
			}
		}
	}

	return 0;
}