/* -*- coding: utf-8 -*-
 *
 * 2227.cc:  No.2227 King Kraken's Attack - yukicoder
 */

#include<cstdio>
#include<algorithm>

using namespace std;

/* constant */

const long long LINF = 1LL << 62;

/* typedef */

typedef long long ll;

/* global variables */

ll check(int h, int w, int la, int lb, int ka, int kb, ll hp, ll vp) {
  ll dh = min(hp * la, (ll)h), dv = min(vp * lb, (ll)w);
  return min(hp * ka + vp * kb + dh * dv, (ll)h * w);
}

ll calcvp(int h, int w, int la, int lb, int ka, int kb, ll hp) {
  ll hw = (ll)h * w;
  ll vp0 = -1, vp1 = hw - hp;
  while (vp0 + 1 < vp1) {
    ll vp = (vp0 + vp1) / 2;
    if (check(h, w, la, lb, ka, kb, hp, vp) >= hw) vp1 = vp;
    else vp0 = vp;
  }
  return vp1;
}

/* subroutines */

/* main */

int main() {
  int h, w, la, lb, ka, kb;
  scanf("%d%d%d%d%d%d", &h, &w, &la, &lb, &ka, &kb);
  ll hw = (ll)h * w;

  ll hp0 = 0, hp1 = hw;
  while (hp0 + 2 < hp1) {
    ll hp00 = (hp0 * 2 + hp1) / 3;
    ll hp01 = (hp0 + hp1 * 2) / 3;
    ll s0 = calcvp(h, w, la, lb, ka, kb, hp00) + hp00;
    ll s1 = calcvp(h, w, la, lb, ka, kb, hp01) + hp01;
    if (s0 > s1) hp0 = hp00;
    else hp1 = hp01;
  }

  ll mins = LINF;
  for (ll hp = hp0; hp <= hp1; hp++)
    mins = min(mins, calcvp(h, w, la, lb, ka, kb, hp) + hp);

  printf("%lld\n", mins);
  return 0;
}