#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

//26 letters in ASCII
//cipher = 1st line. intercepted = 2nd line

//check if char is a letter
int isletter(char *cipher, char *intercepted)
{
  for (int i = 0; cipher[i] != '\0'; i++)
  {
    if (!isalpha(cipher[i]))
    {
      return 1;
    }
  }
  for (int i = 0; intercepted[i] != '\0'; i++)
  {
    if (!isalpha(intercepted[i]))
    {
      return 1;
    }
  }
  return 0;
}

//compare length of cipher and intercepted
int compare_length(char *cipher, char *intercepted)
{
  for (int i = 0;; i++)
  {
    if (((cipher[i]) == '\0' && (intercepted[i]) != '\0') || ((intercepted[i]) == '\0' && (cipher[i]) != '\0'))
    {
      return 1;
      break;
    }
    else if (cipher[i] == '\0' && intercepted[i] == '\0')
    {
      return 0;
      break;
    }
  }
}

int main(int argc, char *argv[])
{
  //load the cipher
  char *cipher;
  cipher = (char *)malloc(1 * sizeof(char));
  int counter = 0;
  while (1)
  {
    scanf("%c", cipher + counter);

    if (cipher[counter] == '\n')
    {
      cipher[counter] = '\0';
      break;
    }
    counter++;
    cipher = realloc(cipher, counter+1);
  }

  //load the intercepted text
  char *intercepted;
  intercepted = (char *)malloc(1 * sizeof(char));
  counter = 0;
  while (1)
  {
    scanf("%c", intercepted + counter);

    if (intercepted[counter] == '\n')
    {
      intercepted[counter] = '\0';
      break;
    }
    counter++;
    intercepted = realloc(intercepted, counter+1);
  }

  //error messages
  if (isletter(cipher, intercepted) == 1)
  {
    fprintf(stderr, "Error: Chybny vstup!\n");
    free(cipher);
    free(intercepted);
    return 100;
  }
  else if (compare_length(cipher, intercepted) == 1)
  {
    fprintf(stderr, "Error: Chybna delka vstupu!\n");
    free(cipher);
    free(intercepted);
    return 101;
  }

  //the thing for the Caesar cipher!
  int size_cipher = strlen(cipher)+1;
  counter = 0;
  char decrypted[size_cipher];

  //shift in alphabet
  for (int i = 0; i <= 52; i++)
  {
    //compare cipher and intercepted text
    int temp_counter = 0;
    for (int j = 0; cipher[j] != '\0'; j++)
    {
      if (cipher[j] == intercepted[j])
      {
        temp_counter += 1;
      }
    }
    //getting new decrypted message
    if (temp_counter >= counter)
    {
      counter = temp_counter;
      strncpy(decrypted, cipher, size_cipher);
    }
    //shift the cipher
    for (int k = 0; cipher[k] != '\0'; k++)
    {
      cipher[k] = cipher[k] + 1;
      if (cipher[k] == 123)
      {
        cipher[k] = 'A';
      }
      else if (cipher[k] == 91)
      {
        cipher[k] = 'a';
      }
    }
  }

  printf("%s\n", decrypted);
  //free the memory
  free(cipher);
  free(intercepted);
  return 0;
}