OPEN "input.txt" FOR INPUT AS #1
OPEN "output.txt" FOR OUTPUT AS #2
CLS
INPUT x$
m = LEN(x$)
FOR n = 1 TO m
a$ = MID$(x$, n, 1)
IF a$ = "(" THEN c = c + 1
IF a$ = ")" THEN v = v + 1
IF a$ = "[" THEN b = b + 1
IF a$ = "]" THEN z = z + 1
NEXT n
IF c = v AND b = z THEN GOTO 100
FOR n = 1 TO c - v
x$ = x$ + ")"
NEXT n
FOR n = 1 TO v - c
x$ = "(" + x$
NEXT n
FOR n = 1 TO b - z
x$ = x$ + "["
NEXT n
FOR n = 1 TO z - b
x$ = "]" + x$
NEXT n
100 PRINT x$
CLOSE
SYSTEM