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.h>
#include <cstdio>
using namespace std;
char str1[82];
char str2[82];
void trans(char *orj,char *dest)
{
    int k=0,len=strlen(orj);
    bool ischk=false;
    for(int y=1;y<=26&&!ischk;y++)
    {
        for(int x=0;x<len;x++)
        {
            if(orj[x]>='a'&&orj[x]<='z')k=orj[x]-'a';
            else if(orj[x]>='A'&&orj[x]<='Z')k=orj[x]-'A';
            k=(k+y)%26;
            if(orj[x]>='a'&&orj[x]<='z')dest[x]='a'+k;
            else if(orj[x]>='A'&&orj[x]<='Z')dest[x]='A'+k;
            else dest[x]=orj[x];
        }
        if(strstr(dest,"the")!=NULL||strstr(dest,"this")!=NULL||strstr(dest,"that"))ischk=true;
    }

}
int main()
{
    while(gets(str1))
    {
        memset(str2,'\0',sizeof(str2));
        trans(str1,str2);
        printf("%s\n",str2);
    }
    return 0;
}

C++: #include <cctype>
#include <cstdio>
#include <cstring>

using namespace std;

bool includes_keyword(const char *str) {
  const static char *keywords[] = { "the", "this", "that" };
  for (const auto keyword : keywords) {
    char *pos = strstr(str, keyword);
    if (pos == NULL) { continue; }
    if (pos != str && isalpha(pos[-1])) { continue; }
    if (isalpha(pos[strlen(keyword)])) { continue; }
    return true;
  }
  return false;
}

int main() {
  while (!feof(stdin)) {
    char cipher[81];
    fgets(cipher, 81, stdin);

    size_t len = strlen(cipher);
    if (cipher[len - 1] == '\n') { cipher[len - 1] = '\0'; }

    char c = 'z';
    for (int i = 0; i < len; ++i) {
      if (isalpha(cipher[i]) && c > cipher[i]) { c = cipher[i]; }
    }
    int shift_begin = 'a' - c;
    int shift_end = shift_begin + 26;
    char decoded[81];
    for (int shift = shift_begin; shift < shift_end; ++shift) {
      strcpy(decoded, cipher);
      for (int i = 0; i < len; ++i) {
        if (isalpha(decoded[i])) { decoded[i] += shift; }
      }
      if (includes_keyword(decoded)) { break; }
    }

    puts(decoded);
  }

  return 0;
}

C++: //#define _USE_MATH_DEFINES
//#include <cmath>
#include <iostream>
//#include <stdio.h>
//#include <stdlib.h>
//#include <iomanip>
#include <vector>
#include <string>
//#include <algorithm>
//#include <functional>
//#include <time.h>
#include <sstream>

using namespace std;


int main(){

	string s,sc, buf;
	stringstream ss;
	vector <string> as;
	int dif = 0;


	while (getline(cin, s)){
		sc += s;
		for (int i = 0; i < sc.size(); i++){
			if (sc[i] == '.')sc[i] = ' ';
		}
		ss << sc;

		while (ss >> buf){
			//the this that???????´¢
			if (buf.size() == 3){
				if ((buf[0] - buf[1]) == 12 && (buf[0] - buf[2]) == 15){
					dif = buf[0] - 't';
					break;
				}
			}
			else if (buf.size() == 4){
				if ((buf[0] - buf[1]) == 12 && (buf[0] - buf[2]) == 11 && (buf[0] - buf[3]) == 1){
					dif = buf[0] - 't';
					break;
				}
				if ((buf[0] - buf[1]) == 12 && (buf[0] - buf[2]) == 19 && (buf[0] - buf[3]) == 0){
					dif = buf[0] - 't';
					break;
				}
			}
		}

		for (int i = 0; i < s.size(); i++){
			if (s[i] >= 'a' && s[i] <= 'z') {
				s[i] -= dif;
				if (s[i] < 'a') s[i] += 26;
				if (s[i] > 'z') s[i] -= 26;
			}
		}

		cout << s << endl;
	}




	return 0;
}

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;
	for(;getline(cin,str);){
		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 <algorithm>
#include <iostream>
#include <cstdio>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include <queue>
#include <string.h>
using namespace std;

#define ISEQ(c) (c).begin(), (c).end()
typedef long long ll;

int main() {
  char s[90];
  while (fgets(s, 81, stdin) != 0) {
    for (int i = 0; i < 26; i++) {
      for (int j = 0; j < strlen(s); j++) {
	if (isalpha(s[j])) {
	  if (s[j] == 'z') s[j] = 'a';
	  else s[j]++;
	}
      }
      if (strstr(s, "the") != NULL or strstr(s, "this") != NULL or strstr(s, "that") != NULL) break;
    }
    printf("%s", s);
  }
}

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

int main() {
	string cipher;
	getline(cin, cipher);
	
	for (int i = 0; i < 26;i++) {
		for (unsigned int n = 0;n < cipher.length();n++) {
			if (cipher.at(n) == 'z') {
				cipher.at(n) = 'a';
			}else if(cipher.at(n)>='a'&&cipher.at(n)<='y'){
				cipher.at(n)++;
			}
		}

		if (cipher.find("the") != string::npos || 
			cipher.find("this") != string::npos ||
			cipher.find("that") != string::npos) {
			cout << cipher << endl;
		}
	}
	
	
	return 0;
}

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



int main(int argc, const char * argv[])
{
    while (1) {
        string word;
        getline(cin, word);
        int cnt = 0;
        for (char tmp2 = word[0]; tmp2 < 'z'; tmp2++) {
            if (tmp2 == 't') {
                break;
            }
            cnt++;
        }
        cnt = 0;
        for (char tmp2 = word[0]; tmp2 > 'a'; tmp2--) {
            if (tmp2 == 't') {
                break;
            }
            cnt--;
        }
        for (int i = 0; i < word.size(); i++) {
            if (word[i] == '.') {
                
            }
            else if (word[i] != ' ') {
                word[i] += cnt;
            }
        }
        cout << word << endl;
    }

    
    return 0;
}