def get_cost(coins, amount):
    if amount == 0:
        return 0
    min_cost = float('inf')
    for coin in coins:
        if amount >= coin:
            min_cost = min(min_cost, 1 + get_cost(coins, amount - coin))
    return min_cost

coins = [2];
amount = 3
cost = get_cost(coins, amount)
if cost == float('inf'):
    print -1
print cost