def permutation(n,r)
	result=1
	for i in 0..r-1 do
		result*=n-i
	end
	return result
end

def factorial(x)
	result=1
	for i in 1..x do
		result*=i
	end
	return result
end

def solve(n,m,r)
	if n+r-n*m-1<n-1||n+r-n*m-1<0||n-1<0 then
		return 0
	end
	return permutation(n+r-n*m-1,n-1)/factorial(n-1)
end

n,m,r=gets.split(/\s/).map{|x|x.to_i}
puts solve(n,m,r)