import itertools
from typing import Iterable
 
def count_lifts(seq: Iterable[int], strength: int) -> int:
    liftn = 1
    subtotal = 0
    for candy in seq:
        if candy + subtotal > strength:
            liftn += 1
            subtotal = 0
        subtotal += candy
    return liftn
def minimal_lifts(candies: Iterable[int], strength: int) -> int:
    return (-1 if max(candies) > strength
            else min(count_lifts(s, strength)
                for s in itertools.permutations(candies)))
 
if __name__ == "__main__":
    # input format:
    # <candy 1> <candy 2> ... <candy n>
    # <strength>
    cs = [int(t) for t in input().split()]
    x = int(input())
    print(minimal_lifts(cs, x))