import math

a, b, k = map(int, input().split())

t = math.lcm(a, b)
l, r = 0, pow(10, 9)

while r - l > 1:
    mid = (l + r) // 2
    if mid // a + mid // b - mid // t >= k:
        r = mid
    else:
        l = mid

print(r)