package main

import (
	"fmt"
)

func min(x, y int) int {
	if y < x {
		return y
	}
	return x
}

func main() {
	var Aw, Ab, Bw, Bb, C, D int
	fmt.Scan(&Aw, &Ab, &Bw, &Bb, &C, &D)
	if C > Ab {
		Aw -= C - Ab
		Bw += C - Ab
	}
	Aw += min(D, Bw)
	fmt.Println(Aw)
}