from math import gcd

a, b, k = map(int, input().split())
lcm_ab = a * b // gcd(a, b)
l, r = 0, max(a * k, b * k)
while r - l > 1:
    mid = (l + r) // 2
    cnt = mid // a + mid // b - mid // lcm_ab
    if cnt >= k:
        r = mid
    else:
        l = mid
print(r)