from sys import stdin
import math
A,B,K = map(int,stdin.readline().split())
g = A*B // math.gcd(A,B)

l = 0
r = (A+B)*K

while r-l != 1:

    m = (l+r)//2

    now = m // A + m // B - m // g
    if now >= K:
        r = m
    else:
        l = m

    #print (m,now)

print (r)