import sequtils,strutils,math
var
    C, D, Aw, Ab, Bw, Bb : int
(Aw, Ab) = stdin.readline.split.map(parseInt)
(Bw, Bb) = stdin.readline.split.map(parseInt)
(C, D) = stdin.readline.split.map(parseInt)

if C <= Ab:
    Ab -= C
    Bb += C
else:
    C -= Ab
    Bb += Ab
    Ab = 0
    Aw -= C
    Bw += C
Aw += min(D, Bw)
echo Aw