#!/usr/bin/python
# -*- coding: utf-8 -*-

Aw, Ab = map(int, raw_input().split())
Bw, Bb = map(int, raw_input().split())
C ,  D = map(int, raw_input().split())

if Ab - C >= 0:
       	Bb += C
else:
       	Aw -= C - Ab
       	Bw += C -Ab
       	Bb += Ab
       	Ab = 0

if Bw - D >= 0:
       	print Aw + D
else:
       	print Aw + Bw