CLS
cislos = 0
'OPEN "input.txt" FOR OUTPUT AS #1
'PRINT #1, "3"
'PRINT #1, "5 2"
'PRINT #1, "5 7 2"
'PRINT #1, "7 8 3 2"
'CLOSE #1
OPEN "input.txt" FOR INPUT AS #1
LINE INPUT #1, a$
CLOSE #1
IF LEN(a$) > 1 THEN GOTO 1.2
1.1
FOR e = 48 TO 57
IF a$ = CHR$(e) THEN chislo = e - 48
NEXT e
1.2
IF a$ = "11" THEN chislo = 11
IF a$ = "12" THEN chislo = 12
IF a$ = "13" THEN chislo = 13
IF a$ = "14" THEN chislo = 14
IF a$ = "15" THEN chislo = 15
DIM a$(chislo): DIM a(chislo): DIM b$(500): DIM b(500): DIM c(500)
OPEN "input.txt" FOR INPUT AS #1
LINE INPUT #1, a$
FOR e = 1 TO chislo
LINE INPUT #1, a$(e)
NEXT e
CLOSE #1
w = 1
FOR e = 1 TO chislo
FOR i = 1 TO LEN(a$(e))
IF MID$(a$(e), i, 1) <> " " THEN b$(w) = b$(w) + MID$(a$(e), i, 1) ELSE w = w + 1
NEXT i

FOR t = 1 TO w
IF b$(t) = "30" THEN b(t) = 30: GOTO 1.5
IF LEN(b$(t)) > 1 THEN GOTO 1.3
FOR u = 48 TO 57
IF b$(t) = CHR$(u) THEN b(t) = u - 48
NEXT u
GOTO 1.51
1.3
IF LEFT$(b$(t), 1) = "1" THEN GOTO 1.31
IF LEFT$(b$(t), 1) = "2" THEN GOTO 1.32
1.31
FOR u = 48 TO 57
IF MID$(b$(t), 2, 1) = CHR$(u) THEN b(t) = 10 + (u - 48)
NEXT u
GOTO 1.5
1.32
FOR u = 48 TO 57
IF MID$(b$(t), 2, 1) = CHR$(u) THEN b(t) = 10 + (u - 48)
NEXT u
GOTO 1.5
1.5
b$(t) = ""
NEXT t
w = 1
IF e > 1 THEN GOTO 1.51
FOR z = 1 TO t - 3
IF b(z) <> 0 AND b(z) <= b(z + 1) THEN c(1) = b(z)
IF b(z + 1) <> 0 AND b(z + 1) <= b(z + 1) THEN c(1) = b(z + 1)
NEXT z
SLEEP: PRINT c(1)
1.51
FOR z = 1 TO t - 3
IF b(z) <= b(z + 1) AND b(z) <> c(e - 1) AND b(z) <> 0 THEN c(e) = b(z)
IF b(z + 1) < b(z) AND b(z + 1) <> c(e - 1) AND b(z) <> 0 THEN c(e) = b(z + 1)
'PRINT b(z)
NEXT z
'PRINT c(e)
IF c(e) = 0 THEN GOTO 1.6 ELSE GOTO 1.55
NEXT e
1.55
OPEN "output.txt" FOR OUTPUT AS #1
PRINT #1, c(e)
CLOSE #1
GOTO 1.7
1.6
ot$ = "-1"
OPEN "output.txt" FOR OUTPUT AS #1
PRINT #1, ot$
CLOSE #1
OPEN "output.txt" FOR INPUT AS #1
WHILE NOT EOF(1)
LINE INPUT #1, d$
PRINT d$
WEND
CLOSE #1
1.7
SYSTEM