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 <cstdio>
#include <iostream>
#include <cstring>

using namespace std;

char data[26]={'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'};
char trans[100];
char mozi;
int position=0;
int zoom;
int first_check=0,first_position=0;
int now;
char result;
int flag = 0;

int main(){
	while(flag == 0){
		scanf("%c",&mozi);
		if(first_check == 0)

		for(int i=0;i<26 && first_check == 0;i++){
			if(mozi == data[i]){
				first_position = i;
				zoom = first_position - 19;
				first_check = 1;
				break;
			}
		}




		if(mozi == ' ' || mozi == '.' || mozi == '\n'){
			if(mozi == ' ' || mozi == '.'){
				trans[position] = mozi;
				position++;
			}

			if(mozi == '\n'){
				//trans[position] = '\n';
				printf("%s\n",trans);
				first_check = 0;
				position = 0;
				memset(trans,'\0',sizeof(trans));
				flag = 1;
			}
		}else{
			for(int i=0;i<26;i++){
				if(data[i] == mozi){
					now = i;
					break;
				}
			}

			trans[position] = data[now - zoom];
			position++;

		}
	}
}

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

char str[128] = { 0 };

inline char nxt(char c) {
	if (c == 'z') {
		c = 'a';
	}
	else if (c >= 'a' && c < 'z') {
		c++;
	}
	return c;
}

bool find() {
	int p = 0;
	while (str[p] != '\0') {
		if (str[p] == 't' && str[p + 1] == 'h') {
			if (str[p + 2] == 'e') {
				return true;
			}
			else if (str[p + 2] == 'i' && str[p + 3] == 's') {
				return true;
			}
			else if (str[p + 2] == 'a' && str[p + 3] == 't') {
				return true;
			}
		}
		p++;
	}
	return false;
}

int main(){
	while (fgets(str, sizeof(str), stdin) != NULL) {
		str[strlen(str) - 1] = '\0';
		for (int i = 0; i < 25; i++) {
			int p = 0;
			while (str[p] != '\0') {
				str[p] = nxt(str[p]);
				p++;
			}
			if (find()) {
				printf("%s", str);
				break;
			}
		}
	}


	return 0;
}

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

int size;
string str;
void change()
{
  for (int i = 0; i < size; i++){
    if ('a' <= str[i] && str[i] <= 'y'){
      str[i]++;
    }
    else if (str[i] == 'z'){
      str[i] = 'a';
    }
  }
}

int main()
{
 // string str;

  while (getline(cin, str), str != ""){
    size = str.size();

    for (;;){
      if (str.find("the") != -1 || str.find("this") != -1 || str.find("that") != -1){
        cout << str << endl;
        break;
      }
      change();
    }
    str = "";
  }
  return 0;
}

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

int main(){
    char THIS[] = "this";
    char THE[] = "the";
    char THAT[] = "that";
    
    while(feof(stdin) == 0){
        char str[81];
        fgets(str,80,stdin);
        if(str[0] == 0) break;
        
        int str_cnt = 0;
        int z = 0;
        while(str_cnt < strlen(str)){
            char key[10];
            int offset;
            sscanf(&str[str_cnt],"%s ",key);
            str_cnt += strlen(key) + 1;
            
            switch(strlen(key)){
            case 3:
                offset = THE[0] - key[0];
                if(THE[1] - key[1] == offset && THE[2] - key[2] == offset){
                    z = offset;
                    str_cnt = 999999;
                    break;
                }
                break;
            case 4:
                offset = THIS[0] - key[0];
                if(THIS[1] - key[1] == offset && THIS[2] - key[2] == offset && THIS[3] - key[3] == offset){
                    z = offset;
                    str_cnt = 999999;
                    break;
                }
                if(THAT[1] - key[1] == offset && THAT[2] - key[2] == offset && THAT[3] - key[3] == offset){
                    z = offset;
                    str_cnt = 999999;
                    break;
                }
                break;
            }
        }
        //z *= -1;
        for(int i = 0;i < strlen(str);i++){
            if(str[i] != '\n'){
            if(str[i] != ' ' && str[i] != '.') printf("%c",str[i]+z);
            else                               printf("%c",str[i]); 
            }
                
            }
            printf("\n");
    }
}

C++: #include<stdio.h>
#include<string>
#include<stdlib.h>
#include<math.h>
#include<iostream>
#include<vector>
#include<algorithm>
#include<numeric>
#include<string.h>
#include<map>
#include<queue>

using namespace std;

typedef pair<int,int> pii;

#define rep(i,j) for(int i=0;i<(j);i++)
#define reps(i,j,k) for(int i=j;i<=k;i++)
#define in(i,j,k) ((i)>=(j)&&(i)<=(k))


int main(){
	char s[81],c,f=1;
	int l,p;
	for(;;){
		p=0;
		do{
			c=getchar();
			s[p++]=c;
		}while(c!=EOF && c!='\n');
		s[p-1]=0;
		l=strlen(s);
		while(strstr(s,"the")==NULL && strstr(s,"that")==NULL && strstr(s,"this")==NULL){
			rep(i,l){
				if(in(s[i],'a','z')){
					s[i]++;
					if(s[i]>'z')s[i]-=26;
				}
			}
		}
		puts(s);
		if(c==EOF)break;
	}
	return 0;
}

C++: #include <iostream>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <algorithm>
#include <stdlib.h>
#include <vector>
#include <stack>

using namespace std;


int main(){
	string line;

	while(getline(cin, line)){
		int flag;

		for(int i=0 ; i<26 ; i++){
			for(int j=0 ; j<line.size() ; j++){
				if(line[j] != ' ' && line[j] != '.'){
					if(line[j] == 'a'){
						line[j] = 'z' ;
					}else{
						line[j]--;
					}
				}
			}

			for(int k=0 ; k<line.size()-2 ; k++){
				if(line[k] == 't' && line[k+1] == 'h'){
					flag = 1;
					break;
				}
			}
			if(flag == 1) break;
		}
		cout << line << endl;
	}
	return 0;
}

C++: #include<stdio.h>
#include<string>
#include<stdlib.h>
#include<math.h>
#include<iostream>
#include<vector>
#include<algorithm>
#include<numeric>
#include<string.h>
#include<map>
#include<queue>

using namespace std;

typedef pair<int,int> pii;

#define rep(i,j) for(int i=0;i<(j);i++)
#define reps(i,j,k) for(int i=j;i<=k;i++)
#define in(i,j,k) ((i)>=(j)&&(i)<=(k))


int main(){
	char s[81],c;
	int l,p;
	while(gets(s)!=NULL){
		l=strlen(s);
		while(strstr(s,"the")==NULL && strstr(s,"that")==NULL && strstr(s,"this")==NULL){
			rep(i,l){
				if(in(s[i],'a','z')){
					s[i]++;
					if(s[i]>'z')s[i]-=26;
				}
			}
		}
		puts(s);
	}
	return 0;
}