def fact(i)
    if i == 0 then
        return 1
    end
    
    return i * fact(i - 1)
end

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

if r - n * m < 0 then
	puts "0"
else
	p fact(n) / fact(r - n * m) / fact(n - r + n * m)
end