n, m, k = gets.split.map(&:to_i)
P = 10**9 + 7

def comb(a, b)
  (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 recip(x)
  pow(x, P - 2)
end

def pow(x, n)
  if (n == 0)
    1
  elsif (x == 0)
    0
  else
    q, r = n.divmod(2)
    y = (pow(x, q) ** 2) % P
    (r == 0) ? y : (x * y) % P
  end
end

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)
