

def combination(n, r)
  (r + 1 .. n).reduce(&:*) / (1 .. (n - r)).reduce(&:*)
end
(n, m, r) = gets.split(' ').map{|i|i.to_i}

if (r < n * m)
   puts 0
else
   puts combination(r - n * m + n - 1, n - 1)
end
