Their pyramid is a bit weird, as it is actually a pyramid-shaped wall - it's flat. The pyramid is stacked according to one simple principle: each lower layer contains one block more than the layer above.
Your task is to write a program which reads the number of blocks the builders have, and outputs the height of the pyramid that can be built using these blocks.
Note: the height is measured by the number of fully completed layers - if the builders don't have a sufficient number of blocks and cannot complete the next layer, they finish their work immediately.
