from math import gcd
A,B,K = map(int,input().split())
lcm = (A*B)//gcd(A,B)
l = 1
r = A*B*K
while abs(r-l) > 1:
    mid = (l+r)//2
    if mid//A+mid//B-mid//lcm >= K:
        r = mid
    else:
        l = mid
print(r)