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

# 最小公倍数
AB = math.lcm(A, B)

# n 以下の A または B の倍数の個数は K個あるか？
def solve(n):
    cnt = n//A + n//B - n//AB
    return cnt >= K

# solve(n) == True となる最小のnが答え

ok = A*K
ng = 0
while abs(ok - ng) != 1:
    mid = (ok + ng)//2
    if solve(mid):
        ok = mid
    else:
        ng = mid
print(ok)