Connect to zero

Connect matching numbers and reduce 30 boards to zero !Your task is to clear 30 squared boards filled with numbers from 0 to B, by matching and connecting 2 numbers in the same row or column. After the connection was made everything inside the selection will be reduced down to zero.Sounds simple, no ?! But to finish most of the boards you'll need planning and strategy. Do it wrong and you'll be restarting a lot...PS: even if you have zeros inside the connection, it is a valid move !