import math

A, B, K = map(int, input().split())

l = min(A, B)
r = max(A, B) * K

C = A * B / math.gcd(A, B)

while l < r:
    m = (l+r) // 2
    a = m // A
    b = m // B
    c = m // C
    if a + b - c == K:
        m = max(a * A, b * B)
        break
    elif a + b - c < K:
        l = m
    else:
        r = m
print(m)