CLS

OPEN "input.txt" FOR RANDOM AS #1
OPEN "output.txt" FOR RANDOM AS #2

GET #1, 1, k$
GET #1, 2, c$
GET #1, 3, n$

k = LEN(c$) - (LEN(c$) - 1) / 2

DIM b$(k)

DIM a$(k)

FOR i = 1 TO k
m(i) = i
NEXT i

FOR i = 1 TO k
b$(i) = LEFT$(c$, i)
a$(i) = RIGHT$(b$, 1)
NEXT i

IF a$(n) = " 0" THEN u = 1
IF a$(n) = " 0" THEN SYSTEM

u = 1

WHILE a$(n) <> n$ AND a$(n) <> " 0"

n$ = a$(n)
u = u + 1

WEND

PUT #2, u

SYSTEM