#coding: UTF-8

import sys
import re
import itertools
from math import log
from collections import deque

### defs ###


### main ###
A = list(map(int,sys.stdin.readline().split()))
B = list(map(int,sys.stdin.readline().split()))
C,D = map(int, sys.stdin.readline().split())
A[0] -= max(0, C-A[1])
B[0] += max(0, C-A[1])
A[0] += min(D, B[0])
print(A[0])