# 

INF = (int)(1e9)
h, w, la, lb, ka, kb = map(int, input().split())
amx, bmx = (h+la-1) // la, (w+lb-1) // lb
bcnt, res = bmx + 1, INF

for acnt in range(amx+1):
    alen = min(h, acnt*la)
    adda = acnt * ka
    while bcnt > 0:
        blen = min(w, (bcnt-1)*lb)
        addb = (bcnt-1) * kb
        if alen*blen+adda+addb < h*w:
            break
        bcnt -= 1
    if bcnt <= bmx:
        res = min(res, acnt+bcnt)

print(res)