Go: package main

import (
	"bufio"
	"os"
	"strings"
	"fmt"
)

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func cipher(text string, direction int, int_shift int) string {
	shift, offset := rune(int_shift), rune(26)
	runes := []rune(text)
	for index, char := range runes {
		switch direction {
		case 1:
			if char >= 'a' && char <= 'z'-shift || char >= 'A' && char <= 'Z'-shift {
				char = char + shift
			} else if char > 'z'-shift && char <= 'z' || char > 'Z'-shift && char <= 'Z' {
				char = char + shift - offset
			}
		case -1:
			if char >= 'a'+shift && char <= 'z' || char >= 'A'+shift && char <= 'Z' {
				char = char - shift
			} else if char >= 'a' && char < 'a'+shift || char >= 'A' && char < 'A'+shift {
				char = char - shift + offset
			}
		}
		runes[index] = char
	}
	return string(runes)
}

func main() {
	for {
		infos := strings.Split(nextString(), " ")
		plain := make([]string, len(infos))
		if len(infos) == 0 {
			break
		}
		// println(infos)
		Decryption:
			for i := 0; i < 26; i++ {
				for j := range infos {
					plain[j] = cipher(infos[j], 1, i)
				}
				for j := range plain {
					if plain[j] == "this" || plain[j] == "that" || plain[j] == "the" {
						break Decryption
					}
				}
			}
			fmt.Println(strings.Join(plain, " "))
	}
}

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

char buf[1000];
string enc, ans;

string decrypt(string s, int k) {
  string ret = "";
  for (int i=0; i<s.size(); i++) {
    char c = s[i];
    if ('a' <= c && c <= 'z') {
      ret += ('a' + ((c-'a')+k)%26);
    } else {
      ret += c;
    }
  }
  return ret;
}

int main() {
  while (1) {
    if (fgets(buf, 100, stdin) == NULL) break;
    enc = buf;
    for (int i=1;i<26;i++) {
      ans = decrypt(enc, i);
      if (ans.find("the") != string::npos) break;
      if (ans.find("this") != string::npos) break;
      if (ans.find("that") != string::npos) break;
    }

    printf("%s", ans.c_str());
  }
}

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

    char a[1000];
    while(scanf("%[^\n]",a) != EOF){
        bool flg = 0;
        for(int i = 1; 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] == ' ')flg = 1;
                    if(ans[j+2] == 'i' && ans[j+3] == 's' && ans[j+4] == ' ')flg = 1;
                    if(ans[j+2] == 'a' && ans[j+3] == 't' && 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:;
        fflush(stdin);
    }

    return 0;
}

C++: #include <sstream>
#include <string>
#include <vector>
#include <map>
#include <algorithm>
#include <iostream>
#include <utility>
#include <set>
#include <cctype>
#include <queue>
#include <stack>
#include <cstdio>
#include <cstdlib>
#include <cmath>
using namespace std;

char caesar(int n, char c) {
    int zure = c + n - 'a';
    if (zure < 26) return (char)(c + zure);
    else return (char)('a' + (zure % 26));
}

int main(void) {
    string s, strCopy;
    while (getline(cin, s)) {
        for (int j = 0; j < 26; j++) {
            for (int i = 0; i < s.size(); i++) {
                if (s[i] >= 'a' && s[i] <= 'z') {
                    s[i] = (s[i] == 'z') ? 'a' : s[i]+1;
                }
            }
            if (s.find("the") != string::npos || s.find("this") != string::npos || s.find("that") != string::npos) {
                cout << s << endl;
            }
        }
    }
    return 0;
}

C++: #include<iostream>
using namespace std;
int main()
{
	char key[100] = "";
	
	while (cin.getline(key, sizeof(key))) {

		for (int i = 0; i < sizeof(key); i++)
		{
			//if (key[i] == (int)" ")cout << "space";
			if ((int)key[i] == 0)break;
			if ((int)key[i] <= 122 && (int)key[i] >= 97)
				key[i] = (int)key[i] - 1;
			if (key[i] == 96)key[i] = 122;
		}
		for (int i = 0; i < sizeof(key); i++)
		{
			if ((int)key[i] == 0)continue;
			cout << key[i];
		}
		for (int i = 0; i < sizeof(key); i++)
			key[i] = 0;
	}
	return 0;
}

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

std::string& test_decode(std::string& decoded_text)
{
	for (char& c : decoded_text) {
		if (c == 'a') {
			c = 'z';
		}
		else if (c != '.' && c != ' ') {
			c -= 1;
		}
	}
	return decoded_text;
}

int main()
{
	std::string encrypted_text;

	while (std::getline(std::cin, encrypted_text)) {
		do {
			test_decode(encrypted_text);
		} while (encrypted_text.find("the")  == std::string::npos &&
				 encrypted_text.find("this") == std::string::npos &&
				 encrypted_text.find("that") == std::string::npos);
		std::cout << encrypted_text << std::endl;
	}

	return 0;
}

C++: #include <stdio.h>

int main(void)
{
	char str[80];
	int num, num2;
	int i;
	
	while (fgets(str, 80, stdin) != NULL){
		num = 't' - str[0];
		printf("%d\n", num);
		i = 0;
		while (str[i] != '\0'){
			if (str[i] != '.' && str[i] != ' ' && str[i] != '\n'){
				str[i] += num;
				if (str[i] > 'z'){
					num2 = str[i] - 'z';
					str[i] = num2 + 'a' - 1;
				}
				else if (str[i] < 'a'){
					num2 = 'a' - str[i] - 204;
					str[i] = 'z' - num2 + 1;
				}
			}
			i++;
		}
		printf("%s", str);
	}
	
	printf("\n");
	
	return (0);
}

C++: #include <stdio.h>
#include <string.h>

int main(void){
    char buf[128];
    bool found;
    
    while (gets(buf) != NULL){
        for(int i=0; i<26; i++){
            found = false;
            if (strstr(buf, "th")){
                found = (strstr(buf,"the") != NULL);
                found |= (strstr(buf,"this") != NULL);
                found |= (strstr(buf,"that") != NULL);
            }
            if (found) break;
            for (char *p = buf; *p != '\0'; p++){
                if (*p >= 'a' && *p <= 'z'){
                        *p = (*p - 'a' + 1) % 26 + 'a';
                }
            }
        }
        printf("%s\n",buf);
    }
    
    return 0;
}

C++: #include <stdio.h>
#include <string.h>

char s1[100];
char s2[100];

int main()
{
	while(1)
	{
		if(NULL == fgets(s1,100,stdin))
		{
			break;
		}
		s1[strlen(s1) - 1] = '\0';
		int l = strlen(s1);
		for(int i = 0; i < 26; i++)
		{
			strcpy(s2,s1);
			for(int j = 0; j < l; j++)
			{
				if('a' <= s2[j] && s2[j] <= 'z')
				{
					s2[j] += i;
					if(s2[j] > 'z')
					{
						s2[j] -= 26;
					}
				}
			}
			if(NULL != strstr(s2,"the") || NULL != strstr(s2,"this") || NULL != strstr(s2,"that"))
			{
				printf("%s\n",s2);
				break;
			}
		}
	}
	return 0;
}