a,b,k = map(int, input().split())

import math
from functools import reduce
def lcm_base(x, y):
    return (x * y) // math.gcd(x, y)

l =lcm_base(a,b)

def is_ok(x):
    t = x//a+x//b-x//l
    if t >= k:
        return True
    else:
        return False

ng = 0
ok = a*k
while ng+1 < ok:
    c = (ng+ok)//2
    if is_ok(c):
        ok = c
    else:
        ng = c
print(ok)