func main()
	var n: int :: cui@inputInt() - 1
	var l: int :: cui@inputInt()
	
	var max: int :: l / n
	var isPrime: []bool :: @sieve(max)
	var ans: int :: 0
	for p(2, max)
		if(isPrime[p])
			do ans :+ l - p * n + 1
		end if
	end for
	do cui@print("\{ans}\n")
end func

func sieve(n: int): []bool
	if(n < 2)
		ret [false].repeat(n + 1)
	end if
	var isPrime: []bool :: [false, false] ~ [true].repeat(n - 1)
	for i(2, n)
		if(isPrime[i])
			var j: int :: i * i
			while(j <= n)
				do isPrime[j] :: false
				do j :+ i
			end while
		end if
	end for
	ret isPrime
end func