Garden watering schedule

A community garden needs watering over a season. For each day you are given the cost of hiring someone to water (costs vary by day). The plants survive as long as there are never two consecutive days without watering; any single missed day is fine. You choose which days to hire. Return the minimum total cost of a safe schedule. An empty list costs 0. For example, [10, 1, 10, 1, 10] can skip days 0, 2, and 4 and pay only 2.