stones = sorted([ int(v) for v in input().split() ])

def exchange(inlist):
    first_product, second_product, third_product = 0, 0, 0
    a, b, c = inlist
    first_product = a
    a, b, c = 0, b-a, c-a

    if c <= b *3:
        second_product = ( b + c ) // 4
    else:
        second_product = b
        c = c - 2*b

        third_product = c // 5

    print(first_product+second_product+third_product)
    return

exchange(stones)