var boxA = readLine()!.split(separator: " ").map({Int($0)!})
var boxB = readLine()!.split(separator: " ").map({Int($0)!})
let move = readLine()!.split(separator: " ").map({Int($0)!})

let bMove1 = min(boxA[1], move[0])
let wMove1 = move[0] - bMove1

boxA[0] -= wMove1
boxA[1] -= bMove1

boxB[0] += wMove1
boxB[1] += bMove1

let wMove2 = min(move[1], boxB[0])
let bMove2 = move[1] - wMove2

print(boxA[0] + wMove2)