open System
type Sol() =
    member this.Solve() = 
        let A = stdin.ReadLine().Split() |> Array.map int
        let B = stdin.ReadLine().Split() |> Array.map int
        let [|C;D|] = stdin.ReadLine().Split() |> Array.map int
        
        let rmB = if C > A.[1] then A.[1] else C
        let rmW = (C - rmB)
        A.[0] <- A.[0] - rmW
        A.[1] <- A.[1] - rmB
        B.[0] <- B.[0] + rmW
        B.[1] <- B.[1] + rmB
        
        let rmW = if D > B.[0] then B.[0] else D
        let rmB = (D - rmW)
        B.[0] <- B.[0] - rmW
        B.[1] <- B.[1] - rmB
        A.[0] <- A.[0] + rmW
        A.[1] <- A.[1] + rmB
        
        printfn "%d" A.[0]
        
let mySol = new Sol()
mySol.Solve()