Файлы. В чем ошибка? Почему не работает? Никак не могу понять

CLS
INPUT "Vvedite imya fayla:", n$
OPEN n$ FOR OUTPUT AS #1
INPUT c
RANDOMIZE TIMER
FOR i = 0 TO c - 1
a1(i) = INT(20 * RND) - 20
PRINT a1(i);
WRITE #1, a1(i)
NEXT i
CLOSE #1
  PRINT
 
INPUT "Vvedite imya fayla:", n$
OPEN n$ FOR OUTPUT AS #2
INPUT c
RANDOMIZE TIMER
FOR i = 0 TO c - 1
a2(i) = INT(20 * RND) - 20
PRINT a2(i);
WRITE #2, a2(i)
NEXT i
CLOSE #2
 
OPEN n$ FOR INPUT AS #1
OPEN n$ FOR INPUT AS #2
OPEN "f3.txt" FOR OUTPUT AS #3
INPUT #1, a1(i)
 INPUT #2, a2(i)
 IF a1(i) < a2(i) THEN WRITE #3, a1(i)
  IF a1(i) < a2(i) THEN WRITE #3, a2(i)
PRINT a1(i);
 PRINT a2(i);
CLOSE #1, #2, #3

CLS
RANDOMIZE TIMER
DIM N AS LONG
OPEN "1.txt" FOR OUTPUT AS #1
OPEN "2.txt" FOR OUTPUT AS #2
 
FOR i = 1 TO 20
   N = 100 * RND
   PRINT #1, N
   N = 100 * RND
   PRINT #2, N
NEXT
CLOSE
 
OPEN "1.txt" FOR INPUT AS #1
OPEN "2.txt" FOR INPUT AS #2
OPEN "3.txt" FOR OUTPUT AS #3
 
FOR i = 1 TO 20
   INPUT #1, A
   INPUT #2, B
   IF A < B THEN PRINT #3, A; B
NEXT
CLOSE