from math import sqrt, ceil


def is_enough(width, height, amount, side):
    return amount <= (side // width) * (side // height)


def binary_search(width, height, amount):
    left = 0
    right = ceil(sqrt(amount)) * max(width, height)
    while right - left > 1:
        middle = (left + right) // 2
        if is_enough(width, height, amount, middle):
            right = middle
        else:
            left = middle
    return right


print(binary_search(*map(int, input().split())))