const mod: int :: 1000000007
const kMax: int :: 1000001
var fact: []int
var inv: []int

func main()
	do @fact :: #[@kMax + 1]int
	do @inv :: #[@kMax + 1]int
	var n: int :: cui@inputInt()
	var m: int :: cui@inputInt()
	var ans: int :: comb(m + 1, n + 1)
	do cui@print("\{ans}\n")
	
	func comb(n: int, r: int): int
		if(@fact[0] = 0)
			do @fact[0] :: 1
			for i(1, @kMax)
				do @fact[i] :: @fact[i - 1] * i % @mod
			end for
			do @inv[@kMax] :: math@modPow(@fact[@kMax], @mod - 2, @mod)
			for i(@kMax, 1, -1)
				do @inv[i - 1] :: @inv[i] * i % @mod
			end for
		end if
		ret @fact[n] * @inv[n - r] % @mod * @inv[r] % @mod
	end func
end func