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 "bits/stdc++.h"
#include<unordered_map>
#include<unordered_set>
#pragma warning(disable:4996)
using namespace std;
using ld = long double;
const ld eps = 1e-9;

//// < "d:\d_download\visual studio 2015\projects\programing_contest_c++\debug\a.txt" > "d:\d_download\visual studio 2015\projects\programing_contest_c++\debug\b.txt"


int main() {
	string st;
	vector<string>ths{ " the "," this "," that " };
	while (getline(cin, st)) {
		st.push_back(' ');
		st.insert(st.begin(), ' ');
		for (int i = 0; i < 26; ++i) {
			string nextst(st);
			for (auto&c : nextst) {
				int n = c - 'a';
				if (n < 0 || n >= 26)continue;
				n += i;
				n %= 26;
				c = 'a' + n;
			}
			bool ok = false;
			for (auto th : ths) {
				if (nextst.find(th) != -1)ok = true;
			}
			if (ok) {
				cout << nextst.substr(1,nextst.size()-2) << endl;
				break;
			}
		}
	}
	return 0;
}

C++: #include <iostream>
#include <string.h>
#include <string>
#include <stdio.h>
using namespace std;
int main() {
	char st[1000];
	string w[3]={"the","this","that"};
	int wn[3]={3,4,4},k,i,j,s,f,z;
	while(true) {
    k=0; z=0;
	scanf("%[^\0]",st);
	z=strlen(st);
	f=0;
	for (i=0;i<z;i++) if (!((st[i]>='a' && st[i]<='z') || st[i]=='.' || st[i]==' ' || st[i]=='\n')) f=1;
	if (f==1 || z>80) continue;
	while(k<z) {
		for (i=0;i<3;i++) {
			s=0; f=0;
			if (z<=k+wn[i]) break;
			for (j=0;j<wn[i]-1;j++) if ((w[i][j]-w[i][j+1])==(st[k+j]-st[k+j+1])) s++;
			if (s==wn[i]-1 && (st[k+wn[i]]<'a' || st[k+wn[i]]>'z' ))  { f=1; i=5;}
		}
		if (f==1) break;
		for (k;st[k]>='a' && st[k]<='z';k++);
		k++;
		}
	if (f==0) cout << st; else {
	for (i=0;i<z;i++) if ((st[i]>='a' && st[i]<='z')) cout << (char)(st[i]-(st[k]-'t')) ; else cout << st[i];
	  }
	cout << endl;
	}
	return 0;
	}

C++: #include<cstdio>
#include<cmath>
#include<iostream>
#include<algorithm>
using namespace std;
int main(){
    string str,kaku[3]={"the","this","that"};
    getline(cin,str);
    while(1){
        for(int i=0;i<str.size();i++){
            if('A'<=str[i]&&str[i]<='Y')str[i]++;
            else if(str[i]=='Z')str[i]-=25;
            else if('a'<=str[i]&&str[i]<='y')str[i]++;
            else if(str[i]=='z')str[i]-=25;
        }
        for(int i=0;i<3;i++){
            if(str.find(kaku[i])!=string::npos)goto exit;
        }
    }
exit:
    cout<<str<<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;
	char chr[100];
	for(;gets(chr);){
		str=(string)(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>
#include<vector>
#include<string>

using namespace std;

char returnc(char c){
  if('a'<=c && c<='z'){
    if(c=='z')return 'a';
    return ++c;
  }
  return c;
}
int main(void){
  string s;
  while(getline(cin,s)){

  vector<string> ss;
  string str;
  s+= " ";
  for(int i = 0 ; i < s.size() ; i ++){
    if(s[i] == ' '){
      ss.push_back(str);
      str="";
    }else{
      str+=s[i];
    }
  }
  bool ok=true;
  string out[] = {"this","that","the"};
  while(ok){
    for(int i = 0 ; i < ss.size(); i ++){
      //cout<<ss[i]<<endl;
      for(int j = 0 ; j < ss[i].size() ; j ++){
	ss[i][j] = returnc(ss[i][j]);
      }
      for(int j = 0 ; j < 3 ; j ++){
	if(ss[i] == out[j])ok=false;
      }
    }
  }
  for(int i = 0 ; i < ss.size()-1 ; i ++){
    cout<<ss[i]<<" ";
  }
  cout<<ss[ss.size() - 1]<<endl;
  }
}

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

const char *table = "abcdefghijklmnopqrstuvwxyz";

int search_number(const std::string &s)
{
    const char *key = "this";
    for (unsigned i = 0; i < s.size() - 3; ++i) {
        if ((s[i] > s[i + 1] && s[i] - s[i + 1] == key[0] - key[1])
                || (s[i] < s[i + 1] && s[i + 1] - s[i] == 26 - (key[0] - key[1]))) {
            int n = s[i] - key[0];
            if (table[(s[i + 2] - 'a' - n) % 26] == key[2]
                    && table[(s[i + 3] - 'a' - n) % 26] == key[3])
                return n;
        }
    }
    return 0;
}

int main()
{
    std::string s;
    while (getline(std::cin, s)) {
        int n = search_number(s);
        for (unsigned i = 0; i < s.size(); ++i) {
            if (s[i] != ' ' && s[i] != ',' && s[i] != '.') {
                s[i] = table[(s[i] - 'a' - n) % 26];
            }
        }
        std::cout << s << std::endl;
    }
}

C++: #include <bits/stdc++.h>
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define RFOR(i,a,b) for(int i=(b) - 1;i>=(a);i--)
#define REP(i,n) for(int i=0;i<(n);i++)
#define RREP(i,n) for(int i=n-1;i>=0;i--)

#define PB push_back
#define INF INT_MAX/3
#define ALL(a) (a).begin(),(a).end()
#define CLR(a) memset(a,0,sizeof(a))

typedef long long int ll;

using namespace std;

int main(){

    string s[] = {"the","this","that"};
    string in;
    while(true){
	getline(cin,in);
	if(cin.eof()) break;
	bool f = false;
	int d = 1;
	REP(i,30){

	    f = true;
	    REP(i,in.size()){
		if(in[i] == '.' || in[i] == ' ' || in[i] == '\n') continue;
		in[i]= (char)( 'a' + ( (int)(in[i] - 'a') + d) % 28);
	    }
	    vector<bool> flgs(3,false);
	    for(int i=0;i<in.size();i++){
		REP(j,3){
		    if(in.substr(i,s[j].size()) == s[j]) flgs[j] = true;
		}
	    }
	    if(flgs[0] || flgs[1] || flgs[2]) break;
	}
	cout << in << endl;
    }

    return 0;
}

C++: /*0017 written by iPhone*/
#include <iostream>
#include <string>
#include <cstring>

using namespace std;

int main(){
    string s;
    while(getline(cin, s)){
        for(int i = 0; i < s.size(); i++) s[i]++;
        if(strstr(s.c_str(), "the") || strstr(s.c_str(), "this") || strstr(s.c_str(), "that") ) cout << s, return 0;
    }
    return 0;
}