let primes n =
    let isPrime = Array.create (n + 1) true
    isPrime.[0] <- false
    if n > 0 then
        isPrime.[1] <- false
    let sq =
        n
        |> float
        |> sqrt
        |> int
    for i in 2 .. sq do
        if isPrime.[i] then
            for j in i * i .. i .. n do
                isPrime.[j] <- false
    let mutable result = []
    for i in 2 .. n do
        if isPrime.[i] then
            result <- i :: result
    result

let [| a; b |] =
    stdin.ReadLine().Split()
    |> Array.map int

primes 100
|> List.filter (fun x -> a <= x && x <= b)
|> List.sumBy (fun x -> pown x 3 - pown x 2 + x + 1)
|> printfn "%d"