Вывести на экран слова, содержащие три буквы

CLS
INPUT "vvedite text"; a$
DIM b(LEN(a$)), c$(LEN(a$))
FOR i = 1 TO LEN(a$)
    IF MID$(a$, i, 1) = " " OR MID$(a$, i, 1) = "." THEN k = k + 1: b(k) = i
NEXT
FOR i = 1 TO k
    c$(i) = MID$(a$, b(i - 1) + 1, b(i) - b(i - 1) - 1)
    IF LEN(c$(i)) = 3 THEN PRINT c$(i)
NEXT

INPUT "vvedite text ", a$
FOR i = 1 TO LEN(a$)
IF MID$(a$, i, 1) <> " " AND MID$(a$, i, 1) <> "." THEN
b$ = b$ + MID$(a$, i, 1)
ELSE
IF LEN(b$) = 3 THEN PRINT b$
b$ = ""
END IF
NEXT

INPUT "vvedite text"; a$
FOR i = 1 TO LEN(a$)
    IF MID$(a$, i, 1) = " " OR MID$(a$, i, 1) = "." THEN
        b$ = MID$(a$, k + 1, i - k - 1): k = i 
        IF LEN(b$) = 3 THEN PRINT b$
    END IF
NEXT

INPUT "vvedite text"; a$
FOR i = 1 TO LEN(a$)
    IF MID$(a$, i, 1) = " " OR MID$(a$, i, 1) = "." THEN d = i - k - 1: k = i
    IF d = 3 AND k = i THEN PRINT MID$(a$, i - d, d)
NEXT