#define LOWERCASE_LETTERS "abcdefghijklmnopqrstuvwxyz"
#define UPPERCASE_LETTERS "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
#define LETTERS LOWERCASE_LETTERS UPPERCASE_LETTERS
#define LOWERCASE_LETTERS "abcdefghijklmnopqrstuvwxyz"
#define UPPERCASE_LETTERS "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
#define LETTERS LOWERCASE_LETTERS UPPERCASE_LETTERS