open System
 
let a = Console.ReadLine().Split()
let n = int64(a.[1]) - 1L
let h = int(a.[0]) - 1
 
let f (h:int) (n:int64)= 
    let mutable i = h
    let mutable mv = 0L
    let mutable ans = 0L
    let mutable tmp = 0L
    let mutable temp = 0L
    while i >= 0 do
            if ((n &&& (1L <<< i)) = 0L) then
                temp <- 0L;
            else
                temp <- 1L;
            if (mv <> temp) then
                ans <- ans + ((1L <<< (i + 1)) - 1L);
                mv <- mv ^^^ 1L
            mv <- mv ^^^ 1L
            ans <- ans + 1L
            i <- i - 1
    printfn "%i" ans
 
f h n

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MyA0

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