Model Blocks Area Generator Not working Correctly, What went wrong?

I made this code and I am trying to figure out what went wrong because it start loading blocks than it randomly went weird and didn't finish the task, Help?

-- Get a reference to an existing object
local original = workspace.Block0
local a = -200
local b = 0
local c = -200

while c <200
do
    -- Create the model copy
    local copy = original:Clone()
    -- Parent the copy to the same parent as the original
    copy.Parent = original.Parent
    -- Move the copy so it's not overlapping the original
    copy:MoveTo(Vector3.new(a, b, c))

    a = a + 8

    if a > 200 then
        a = 0
        b = b + 8
    end
    if b > 200 then
        c = c + 8
        a = 0
        b = 0
    end
end