A form is the union of squared rectangles whose bases are consecutive unitary segments in a horizontal line that leaves all the rectangles on the same side, and whose heights m1,...,mn satisying m1≥...≥mn. An angle in a form consists of a box v and of all the boxes to the right of v and all the boxes above v. The size of a form of an angle is the number of boxes it contains. Find the maximum number of angles of size 11 in a form of size 400.[url=http://www.oma.org.ar/enunciados/omr20.htm]source combinatorial geometryrectanglecombinatorics