open System
type Sol() =
    member this.Solve() = 
        let [|N;L|] = stdin.ReadLine().Split() |> Array.map int
        
        let NL = int64 N
        let LL = int64 L
        
        let isPrime = Array.create (L/2 + 100) true
        isPrime.[0] <- false
        isPrime.[1] <- false
        for i = 2 to 1 + int ((sqrt (double (L/2 + 100)))) do
            if isPrime.[i] = true && LL >= ((NL-1L) * (int64 i)) then
                for j in [(i*i)..i..(L/2 + 99)] do isPrime.[j] <- false 
        
        let primes = Seq.zip isPrime [0..(L/2 + 99)] |> Seq.filter (fun (b,p) -> b = true) |>Seq.map snd
        
        let ans:int64 = primes |> Seq.sumBy (fun p -> (( L - ((N-1) * p) + 1 ) |> int64 ) )
        
        printfn "%d" ans
        
        ()
let mySol = new Sol()
mySol.Solve()