def test1():
n = 5
k = 3
h = [10, 30, 40, 50, 20]
cost = B.calc_cost(n, k, h)
assert cost[n - 1] == 30
def test3():
n = 2
k = 100
h = [10, 10]
cost = B.calc_cost(n, k, h)
assert cost[n - 1] == 0
def test4():
n = 10
k = 4
h = [40, 10, 20, 70, 80, 10, 20, 70, 80, 60]
cost = B.calc_cost(n, k, h)
assert cost[n - 1] == 40
def test2():
n = 3
k = 1
h = [10, 20, 10]
cost = B.calc_cost(n, k, h)
assert cost[n - 1] == 20
