A, B, K = gets.split.map(&:to_i)
C = A.lcm(B)

def f(x)
  a = x / A
  b = x / B
  c = x / C

  a + b - c <= K
end

ok = 0
ng = 10 ** 18

while (ok - ng).abs >= 2
  x = (ok + ng) / 2

  if f(A * x)
    ok = x
  else
    ng = x
  end
end

puts A * ok