## Goal

You live in a world where all coins have the same shape, weight and feel. You can't distinguish them in your pocket. Knowing how many coins of each value you have in your pocket, how many should you grab, without looking, to be sure to have enough money to pay?
Input

**Line 1 :** An integer `valueToReach` representing the price you want to be able to pay

**Line 2 :** An integer `N` representing the number of different coin types you have

**Line 3 :** `N` integers separated by space representing the number of coins of each type

**Line 4 :** `N` integers separated by space representing the value of each type

Output

**Line 1 :** A line containing a single integer representing the minimum number of coins you need to grab to be sure to have enough money to pay. -1 if there's not enough money in your pocket

Constraints

1<= ` number of coins ` <=1000

1<= ` coin values ` <=1000

1<= ` N ` <=1000