Sky Road (Unreleased)

You - the chief road Builder in the candy Kingdom! Build roads to unite the city into a single network. The shorter road between the houses - the more profit.

Each turn of the game, road is built up one cell.
Each bridge is worth some money (up to 6 bridges per cell)
Cell types: meadow - 1, forest - 2, mountain - 3, empty - 4 coins for each bridge.
Each city trades with every: the shorter between the road, the higher the profit.
City on the neighboring cells is already connected.
Part of the profits goes to the maintenance of already constructed roads.
How many levels can you go?