#めぐる式二部探索
#参考サイト：https://aotamasaki.hatenablog.com/entry/meguru_bisect
import math

A,B,K = map(int, input().split())
gclcm = (A * B) // math.gcd(A, B)


def is_ok(arg):
    # 整数を買えればTrueを返す
    return arg//A+arg//B-arg//gclcm<K

def meguru_bisect(ng, ok):
    while (abs(ok - ng) > 1):
        mid = (ok + ng) // 2
        if is_ok(mid):
            ok = mid
        else:
            ng = mid
    return ok

print(meguru_bisect(max(A,B)*K, 0)+1)