H, W, LA, LB, KA, KB = map(int, input().split())
HW = H * W
ans = 10 ** 7
ans1 = 10 ** 7
if KA > 0:
    ans1 = min(ans1, -(-HW // KA))
if KB > 0:
    ans1 = min(ans1, -(-HW // KB))
tmp = 10 ** 7
for i in range(H + 1):
    lb = -1
    hb = W + 1
    while hb - lb > 1:
        mid = (lb + hb) // 2
        tmp = min(H, LA * i) * min(W, LB * mid) + KA * i + KB * mid
        if tmp >= HW:
            hb = mid
        else:
            lb = mid
        # print(i,hb,tmp)
    if hb == W + 1:
        continue
    if ans > i + hb:
        ans = i + hb
        # print(i,hb,i+hb)
    else:
        break

print(min(ans,ans1))