Zadacha_1923

def isAnswer(w, h, n, m):
    return (m//w) * (m//h) >= n


def find(w, h, n):
    l = 0
    r = 10**18
    while l + 1 < r:
        m = (l + r)//2
        if isAnswer(w, h, n, m):
            r = m
        else:
            l = m
    return r


w, h, n = list(map(int, input().split()))
        
print(find(w, h, n))