#include <cassert>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <iomanip>
#include <climits>
#include <map>
#include <queue>
#include <set>
#include <cstring>
#include <vector>

using namespace std;
typedef long long ll;

int main() {
  ll H, W, LA, LB, KA, KB;
  cin >> H >> W >> LA >> LB >> KA >> KB;

  ll ans = LLONG_MAX;

  for (ll a = 0; a <= H; ++a) {
    if (a * KA >= H * W) {
      ans = min(ans, a);
    } else {
      ll ok = H * W;
      ll ng = 0;

      while (abs(ok - ng) >= 2) {
        ll x = (ok + ng) / 2;
        ll cnt = min(H, a * LA) * min(W, x * LB) + a * KA + x * KB;

        if (cnt >= H * W) {
          ok = x;
        } else {
          ng = x;
        }
      }

      ans = min(ans, a + ok);
    }
  }

  for (ll b = 0; b <= W; ++b) {
    if (b * KB >= H * W) {
      ans = min(ans, b);
    } else {
      ll ok = H * W;
      ll ng = 0;

      while (abs(ok - ng) >= 2) {
        ll x = (ok + ng) / 2;
        ll cnt = min(H, x * LA) * min(W, b * LB) + x * KA + b * KB;

        if (cnt >= H * W) {
          ok = x;
        } else {
          ng = x;
        }
      }

      ans = min(ans, b + ok);
    }
  }

  cout << ans << endl;

  return 0;
}