Problem Statement

Fill the First Column You are given a rectangular board divided into square cells. Each cell is either occupied by a block ( # ) or empty ( . ). You may add blocks to the board. To add one block: 1. Choose a row r . 2. Insert a new block into the leftmost cell of that row. 3. The block moves right through empty cells until the next cell would be outside the board or already contain a block. 4. From its resulting column, the block falls downward through empty cells until the next cell would be outside the board or already contain a block. 5. The block remains in that final cell. It does not move horizontally again after falling. A block may be inserted only if the leftmost cell of the chosen row is empty at the time of insertion. Your goal is to make every cell in the first column occupied by a block using the minimum possible number of inserted blocks. Output the row indices into which to insert the blocks. If several minimum-length sequences are possible, output the lexicographically