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

def gcd(a,b):
    while True:
        r = a % b
        a = b
        b = r
        if r == 0:return a
L = A * B // gcd(A,B)
def f(x):
    return x // A + x // B - x // L
end = A * K
start = 0
while end - start > 1:
    mid = (end + start) // 2
    if f(mid) >= K:
        end = mid
    else:
        start = mid
print(end)