sub fibonacciI (n)
local n1, n2, k, sum
n1 = 0
n2 = 1
for k = 1 to abs(n)
sum = n1 + n2
n1 = n2
n2 = sum
next k
if n < 1 then
return n1 * ((-1) ^ ((-n) + 1))
else
return n1
end if
end sub