def cell_distance(n, m, k)
  distance_x = 1.upto(n - 1).inject(0) { |sum, d| sum + d * (n - d) } * m ** 2
  distance_y = 1.upto(m - 1).inject(0) { |sum, d| sum + d * (m - d) } * n ** 2
  
  nCr = -> (n, k) {
    k = n - k if 2 * k > n
    return 1 if k == 0
    ((n - k + 1)..n).reduce(&:*) / ((1..k).reduce(&:*))
  }

  mod = 10 ** 9 + 7

  (distance_x + distance_y) * nCr.call(n * m - 2, k - 2) % mod
end

n, m, k = gets.split.map(&:to_i)
puts cell_distance(n, m, k)