import math

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

def find_kth_multiple(A, B, K):
    gcd = math.gcd(A, B)
    lcm = A * B // gcd
    low = 1
    high = max(A, B) * K
    while low < high:
        mid = (low + high) // 2
        count = mid // A + mid // B - mid // lcm
        if count >= K:
            high = mid
        else:
            low = mid + 1
    return low

print(find_kth_multiple(A, B, K))