package main

import (
	"fmt"
	"math"
)

func main() {
	var aw, ab, bw, bb, c, d int
	_, _ = fmt.Scan(&aw, &ab, &bw, &bb, &c, &d)

	if c-d > 0 {
		if c > ab {
			aw -= c - ab
			bw += c - ab
		}
	}
	aw += int(math.Min(float64(bw), float64(d)))

	fmt.Println(aw)
}