1 5 6 9
11

2

coins = list(map(int, input().split()))
amount = int(input())
memo = {}
def min_coins(n):
    if n == 0:
        return 0
    if n < 0:
        return float('inf')
    if n in memo:
        return memo[n]
    res = min(min_coins(n - c) for c in coins) + 1
    memo[n] = res
    return res
result = min_coins(amount)
print(result if result != float('inf') else -1)