h,w,la,lb,ka,kb = map(int,input().split())
ans = (h+la-1)//la + (w+lb-1)//lb

ma = ans
now = 0
nk = 0
for i in range(ma)[::-1]:
    left = max(h-i*la,0)
    k = ka*i

    while k+nk < left*w:
        now += 1
        nk += kb
        if now > ans:
            print(ans)
            exit()
    
    left2 = k+nk - left*w
    
    leftW = h-left
    while True:
        if leftW == 0:
            break
        if now*lb + left2//leftW >= w:
            break
        now += 1
        nk += kb
        left2 += kb

    ans = min(ans,now+i)

    if now > ans:
        break
print(ans)