Chef and His Garden

Chef is an advocate for Go Green Initiative. Today he had n trees planted in a row outside his his restaurant. Today, the height of i-th tree is hi feet. The trees grow at a rate of mi feet per day. Chef knows that trees will look beautiful if they form a zig-zag sequence. The trees will be said to be in Zig-zag sequence if the heights of tree first increases or decreases, then alternates betwee