H,W,LA,LB,KA,KB=map(int, input().split())
if KA==0 and KB==0:
  print((H-1)//LA+(W-1)//LB+2)
  exit()
if KB==0:
  H,W,LA,LB,KA,KB=W,H,LB,LA,KB,KA
import bisect
Y=(H-1)//LA+1
if KA!=0:
  Y=min((H*W-1)//KA+1,Y)
ans=10**10
for y in range(Y+1):
  xx=max(0,H*W-y*KA)
  if xx==0:
    ans=min(ans,y)
  else:
    X=(xx-1)//KB+1
    ng,ok=-1,X+1
    while ok-ng>1:
      mid=(ok+ng)//2
      ko=y*KA+mid*KB+min(H,LA*y)*min(W,LB*mid)
      if ko>=H*W:
        ok=mid
      else:
        ng=mid
    ans=min(ans,y+ok)
print(ans)