P = 10**9 + 7

def comb(a, b)
  b = a - b if (a - b < b)
  # 今回は b <= a < P なので 0割りエラーは起きないはず
  (fac(a, b) * recip(fac(b, b))) % P
end

def fac(a, b)
  (a-b+1 .. a).reduce(1) do |r, i| (r * i) % P  end
end

def e_gcd(n, m, x = 0, last_x = 1, y = 1, last_y = 0)
  if m == 0
    [n, last_x, last_y]
  else
    q, r = n.divmod(m)
    e_gcd(m, r, last_x - q * x, x, last_y - q * y, y)
  end
end

def recip(n)
  d, x, y = e_gcd n, P
  x % P
end

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

c = m**2 * (n+1)*n*(n-1)/6 + n**2 * (m+1)*m*(m-1)/6
d = comb(n*m-2, k-2)

p((c * d) % P)
