there n pile sand ith pile a_i block sand the ith pile call tall 1 n a_i a_i1 a_i1 that pile tall sand neighbour combine note pile end array tallYou give integer k an operation consist pick k consecutive pile sand add unit sand Formally pick 1 leq lr leq n rl1k then l leq leq r update a_i get a_i1what maximum number pile simultaneously tall possibly zero operation