#!/usr/bin/env python3
#fileencoding: utf-8

Aw, Ab = [int(i) for i in input().strip().split(" ")]
Bw, Bb = [int(i) for i in input().strip().split(" ")]
C, D = [int(i) for i in input().strip().split(" ")]

if C <= Ab:
    if D <= Bw:
        print(Aw+D)
    else:
        print(Aw+Bw)
elif C > Ab:
    Bw += (C-Ab)
    Aw = Aw - (C-Ab)
    if D <= Bw:
        print(Aw+D)
    else:
        print(Aw+Bw)