# 

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

for acnt in range(amx+1):
    alen, adda = min(h, acnt*la), acnt * ka
    lval, rval = -1, bmx + 1
    while rval-lval > 1:
        cval = rval - (rval-lval) // 2
        blen, addb = min(w, cval*lb), cval * kb
        if alen*blen+adda+addb < h*w:
            lval = cval
        else:
            rval = cval
    if rval <= bmx:
        res = min(res, acnt+rval)

print(res)