let pDice = [2; 3; 5; 7; 11; 13]
let cDice = [4; 6; 8; 9; 10; 12]
let calExp xs = 
    xs 
    |> List.map float |> List.sum 
    |> fun x -> x/(xs |> List.length |> float)

let pExp = pDice |> calExp
let cExp = cDice |> calExp

let P, C = let t = stdin.ReadLine().Split() |> Array.map int
           in t.[0], t.[1]

let ans = 
    let p = pown pExp P
    let c = pown cExp C
    p*c

ans |> printfn "%f"