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.h>
#include<cstdio>
#include<algorithm>
#include<stack>
#include<queue>
#include<vector>
#include<cmath>
#include<utility>
#define li long long int
#define ld long long double
#define PI 3.1415926535897932384626
#define EPS 0.0000000001
#define rep(i,n) for(i=0;i<n;i++)
using namespace std;
typedef pair<int, int> P;

char str[85];
char word[3][5]={"the","this","that"};
char sent[80][80]={};
int main()
{
  bool ans=false;
  while(1){
    int i=0,j=0;
    int num=0;
    gets(str);
    if(strlen(str)==0)break;
    scanf("%*c");
    for(i=0;num<strlen(str);i++){
      for(j=0;;j++){
	sent[i][j]=str[num];
	num++;
	if(sent[i][j]==' '){
	  sent[i][j]='\0';
	  break;
	}
	if(sent[i][j]=='\0')break;
      }
    }
    //cout<<i<<endl;
    int gap,k,l;
    
    rep(gap,26){
      rep(k,i) rep(l,strlen(sent[k])){
	if(sent[k][l]>='a' && sent[k][l]<'z')
	   sent[k][l]++;//??????????????????
	else if(sent[k][l]=='z')
	  sent[k][l]='a';
      	//cout<<sent[k][l];//debug
      }
      // cout<<endl;//debug
      rep(k,i)
	if(strcmp(sent[k],word[0])==0 || strcmp(sent[k],word[1])==0 
	   || strcmp(sent[k],word[2])==0){
	  rep(l,i){
	    for(int a=0;a<strlen(sent[l]);a++)
	      cout<<sent[l][a];
	    if(l<i-1)
	      cout<<" ";
	    else
	      cout<<endl;
	  }
	  ans=true;
	  break;
	}
      if(ans)break;
    }
  }
}

C++: #define _USE_MATH_DEFINES
#include <iostream>
#include <queue>
#include <vector>
#include <math.h>
#include <algorithm>
#include <iomanip>
#include <string>
#include <stack>
using namespace std;

int main(){
	int gap = 0;
	string s;
	while(getline(cin, s)) {
		for (int i = 0; i < 3; ++i) {
			for (int j = 0; j < 'z' - 'a' + 1; ++j) {
				string cs;
				if (i == 0) cs = "the";
				if (i == 1) cs = "that";
				if (i == 2) cs = "this";
				for (int k = 0; k < cs.length(); ++k) {
					int sum;
					sum = (cs[k] - 'a' + j) % ('z' - 'a' + 1);
					cs[k] = 'a' + sum;
				}
				if (s.find(cs) != string::npos) {

					gap = j;
					break;
				}
			}
			if (gap != 0) break;
		}
		for (int i = 0; i < s.length(); ++i) {
			if ('a' <= s[i] && s[i] <= 'z') {
				int sum;
				sum = (s[i] - 'a' - gap + 'z' - 'a' + 1) % ('z' - 'a' + 1);
				s[i] = sum + 'a';
			}
		}
		cout << s << endl;
	}
	return 0;
}

C++: #include <iostream>
#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;
		break;
	}
}

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

C++: #include <iostream>
#include <string>
using namespace std;
int main(){
      string s;
      while(getline(cin,s)||!cin.eof()){
            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<iostream>
#include<cstring>

using namespace std;

int main(){
  char a[100],b[100];
  for(int i;i<100;i++){
    a[i]='\0';
    b[i]='\0';
  }
  cin>>a;
  int i=0;
  while(i<26){
    for(int j=0;a[j]!='\0';j++){
      if(0x61<=a[j]+i&&a[j]+i<=0x7A)
	b[j]+=i;
      else if(0x61<=a[j]&&a[j]<=0x7A){
	b[j]=a[j]-26+i;
      }
    }
    if(strstr(b,"the")||strstr(b,"this")||strstr(b,"that"))
      break;
    i++;
  }
  for(int k=0;a[k]!='\0';k++)
    cout<<b[k];
  cout<<'\n';
  return 0;
}

C++: #include<cstdio>
#include<cstring>
#include<iostream>
using namespace std;
int main(){

    char a[1000];
    while(scanf("%[^\n]",a) != EOF){
        getchar();
        bool flg = 0;
        for(int i = 0; i < 26; i++){
            unsigned char ans[1000] = {0};
            for(int j = 0; j < strlen(a); j++){
                if(a[j] == ' ' || a[j] == '.') ans[j] = a[j];
                else ans[j] = a[j] + i;
                if(ans[j] > 'z') ans[j] -= 26;
            }
            for(int j = 0; j < strlen(a); j++){
                if(ans[j] == 't' && ans[j+1] == 'h'){
                    if(ans[j+2] == 'e' && ans[j+3] == ' ' || ans[j+3] == 0 || ans[j+3] == '.')flg = 1;
                    if(ans[j+2] == 'i' && ans[j+3] == 's' && ans[j+4] == ' ' || ans[j+4] == 0 || ans[j+4] == '.')flg = 1;
                    if(ans[j+2] == 'a' && ans[j+3] == 't' && ans[j+4] == ' ' || ans[j+4] == 0 || ans[j+4] == '.')flg = 1;
                }
                if(flg){
                    if(j == 0){
                        cout << ans << endl;
                        goto end;
                    }
                    else{
                        if(ans[j-1] == ' '){
                            cout << ans << endl;
                            goto end;
                        }
                    }
                }
            }
        }
        end:;
        for(int i = 0;i < 1000; i++) a[i] = 0;
    }

    return 0;
}

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

string conv(string s, int d) {
  for(int i = 0; i < s.size(); ++i) {
    if(isalpha(s[i])) s[i] = (s[i]-'a'+d)%26+'a';
  }
  return s;
}

int main() {
  string s;
  getline(cin, s);
  for(int i = 0; i < 26; ++i) {
    string t = conv(s, i);
    if(t.find("the") != string::npos ||
       t.find("this") != string::npos ||
       t.find("that") != string::npos) {
      cout << t << endl;
      break;
    }
  }
  return 0;
}