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 <stdio.h>

int str_len(char str[128]) {
	int i = 0;

	while(str[i]) i++;

	return i;
}

/* 二つの文字列が一致すれば1,一致しなければ0をかえす */
int str_comp(char str1[128], char str2[128]) {
	int len;
	int i;

	/* 文字列の長さが一致しなかった場合 */
	if((len = str_len(str1)) != str_len(str2))
		return 0;

	for(i = 0; i < len; i++) {
		if(str1[i] != str2[i])
			return 0;
	}

	return 1;
}

/* char1からchar2への準方向への差を求める */
int deff_two_char(char char1, char char2) {
	int ans;
	if((ans = char2 - char1) < 0)
		ans += 26;

	return ans;
}

/* 文字を順方向へdeffだけずらす */
char shift_letter_deff(int deff, char c) {
	char ans = c;

	if(c - 'a' + deff > 25)
		ans += deff - 26;
	else
		ans += deff;
	
	return ans;
}

/* 単語を準方向へdeffだけずらす */
void shift_deff(int deff, char str[128]) {
	int i = 0;

	while(str[i]) {
		str[i] = shift_letter_deff(deff, str[i]);
		i++;
	}
}

/* 文字列をコピー */
void str_cp(char str1[128], char str2[128]) {
	int i = 0;

	while(str1[i]) {
		str2[i] = str1[i];
		i++;
	}

	str2[i] = '\0';
}

int main() {
	/* 使用する変数の宣言 */
	char input_str[128];
	char dev_word_str[41][80];

	int deff;
	int deff_the = -1;
	int deff_that = -1;
	int deff_this = -1;
	int count_the = 0;
	int count_that = 0;
	int count_this = 0;
	int temp_deff;

	char temp[80];

	int word_sum;
	int letter_sum[40];

	int i, j, k;

	/* 入力を受け取る */
	while(fgets(input_str, 128, stdin) != NULL) {
		/* 各変数の初期化 */
		deff_the = -1;
		deff_that = -1;
		deff_this = -1;
		count_the = 0;
		count_that = 0;
		count_this = 0;

		/* 入力された文字列を単語ごとに分ける */
		i = 0; j = 0; k = 0;
		while(input_str[i]) {
			if(input_str[i] == ' ') {
				dev_word_str[j][k] = '\0';
				letter_sum[j] = k;
				j++;
				k = 0;
			}
			else if(input_str[i] == '.')
				dev_word_str[j][k] = '\0';
			else {
				dev_word_str[j][k] = input_str[i];
				k++;
			}

			i++;
		}

		word_sum = j + 1;

		/* 文字列を比較して、the, that, thisのいずれかがあるか調べる。 */
		for(i = 0; i < word_sum; i++) {
			str_cp(dev_word_str[i], temp);
			temp_deff = deff_two_char(temp[0], 't');
			shift_deff(temp_deff, temp);
			if(str_comp("the", temp)) {
				if(!count_the || deff_the != temp_deff) {
					deff_the = temp_deff;
					count_the++;
				}
			}
			else if(str_comp("that", temp)) {
				if(!count_that || deff_that != temp_deff) {
					deff_that = temp_deff;
					count_that++;
				}
			}
			else if(str_comp("this", temp)) {
				if(!count_this || deff_this != temp_deff) {
					deff_this = temp_deff;
					count_this++;
				}
			}
		}

		/* 比較の結果をもとに、実際いくつずれているか調べる。 */
		if(count_the == 1)
			deff = deff_the;
		else if(count_that == 1)
			deff = deff_that;
		else
			deff = deff_this;
		
		/* 出力 */
		i = 0;
		while(input_str[i]) {
			if(input_str[i] == ' ')
				putchar(' ');
			else if(input_str[i] == '.')
				putchar('.');
			else
				printf("%c", shift_letter_deff(deff, input_str[i]));
			i++;
		}

		putchar('\n');
	}

	return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <vector>
#include <list>
#include <algorithm>
#include <cmath>
#include <stack>
#include <set>
using namespace std;

#define REP(i,n) for(int (i)=0; (i)<(n); (i)++)
#define FOR(i,a,b) for(int (i)=(a); (i)<(b); (i)++)
#define PUSH(n,v) for(int i=0; i<(n); i++) {int j; cin >> j; v.push_back(j);}
#define ALL(v) v.begin(), v.end()

void rot1(string &s) {
    string t = "";
    REP(i,s.size()) {
        if (s[i] > 'a' && s[i] < 'z') {
            if (s[i] == 'a') t += "z";
            else t += s[i] - 1;
        }else {
            t += s[i];
        }
    }
    s = t;
}

int main() {
    string s;
    getline(cin, s);
    while(s.find("the") == string::npos && s.find("this") == string::npos && s.find("that") == string::npos) {
        rot1(s);
    }
    cout << s << endl;
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

//#define int long long
#define reps(i,s,n) for(int (i)=(s);(i)<(n);++(i))
#define rep(i,n) reps(i,0,n)
#define rept(i,n) rep(i,(n)+1)
#define repst(i,s,n) reps(i,s,(n)+1)
#define reprt(i,n,t) for(int (i)=(n);(i)>=(t);--(i))
#define repr(i,n) reprt(i,n,0)
#define each(itr,v) for(auto &(itr):(v))
#define all(c) (c).begin(),(c).end()
#define rall(c) (c).rbegin(),(c).rend()
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define tmax(x,y,z) max(x,max(y,z))
#define tmin(x,y,z) min(x,min(y,z))
#define chmin(x,y) x=min(x,y)
#define chmax(x,y) x=max(x,y)
#define ln '\n'
#define bln(i,n) (((i)==(n)-1)?'\n':' ')
#define dbg(x) cout<<#x" = "<<(x)<<ln<<flush
#define dbga(x,n) {cout<<#x" : ";for(int (i)=0;i<(n);++i){cout<<((x)[i])<<(i==((n)-1)?'\n':' ')<<flush;}}
#define zero(a) memset(a,0,sizeof(a))
#define unq(a) sort(all(a)),a.erase(unique(all(a)),a.end())

typedef complex<double> P;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<string> vst;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<vector<int> > mat;

const ll inf = (ll)1e9+10;
const ll linf = (ll)1e18+10;
const ll mod = (ll)(1e9+7);
const int dx[] = {0, 1, 0, -1};
const int dy[] = {1, 0, -1, 0};
const int ddx[] = {0, 1, 1, 1, 0, -1, -1, -1};
const int ddy[] = {1, 1, 0, -1, -1, -1, 0, 1};
const double eps = 1e-10;

ll mop(ll a,ll b,ll m=mod) {ll r=1;a%=m;for(;b;b>>=1){if(b&1)r=r*a%m;a=a*a%m;}return r;}
ll gcd(ll a,ll b) {return b?gcd(b,a%b):a;}
ll lcm(ll a,ll b) {return a*b/gcd(a,b);}
bool ool(int x,int y,int h,int w) {return((x<0)||(h<=x)||(y<0)||(w<=y));}
bool deq(double a,double b) {return abs(a-b)<eps;}

struct oreno_initializer {
	oreno_initializer() {
		cin.tie(0);
		ios::sync_with_stdio(0);
	}
} oreno_initializer;

// ━━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…
// .｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋
// ・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・

typedef string::const_iterator S;
string s;

//(t.size()>=3 && t.substr(0,3)=="the") || (t.size()>=4 && (t.substr(0,4)=="that" || t.substr(0,4)=="this"))

bool ok(S &i, S &e) {
	if (i==e) return 0;
	string t;
	while (*i!=' ') t.pb(*i), i++;
	if (t=="the" || t=="this" || t=="that") return 1;
	return ok(++i,e);
}

signed main() {
	while (getline(cin,s)) {
		if (s.empty()) break;
		s.pb(' ');
		rep(i,26) {
			S b = s.begin(), c = s.end();
			if (ok(b,c)) {
				cout << s << ln << flush;
				break;
			}
			rep(j,s.size()) if ('a'<=s[j] && s[j]<='z') {
				s[j]++;
				if (s[j]>'z') s[j] = 'a';
			}
		}
	}
}