// #pragma GCC target("avx")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")

#include <bits/stdc++.h>
using namespace std;

#define rep(i,n) for(int i = 0; i < (int)n; i++)
#define FOR(n) for(int i = 0; i < (int)n; i++)
#define repi(i,a,b) for(int i = (int)a; i < (int)b; i++)
#define all(x) x.begin(),x.end()
//#define mp make_pair
#define vi vector<int>
#define vvi vector<vi>
#define vvvi vector<vvi>
#define vvvvi vector<vvvi>
#define pii pair<int,int>
#define vpii vector<pair<int,int>>

template<typename T>
void chmax(T &a, const T &b) {a = (a > b? a : b);}
template<typename T>
void chmin(T &a, const T &b) {a = (a < b? a : b);}

using ll = long long;
using ld = long double;
using ull = unsigned long long;

const __int128_t INF = 1e13;
const ld pi = 3.1415926535897932384626433832795028;
const ll mod = 998244353;
int dx[] = {1, 0, -1, 0, -1, -1, 1, 1};
int dy[] = {0, 1, 0, -1, -1, 1, -1, 1};

#define int long long

void solve() {
    int h, w, la, lb, ka, kb;
    cin >> h >> w >> la >> lb >> ka >> kb;

    int ans = INF;

    rep(i, (h+la-1)/la+1) {
        int line = min(h, i * la);

        __int128_t l = 0, r = INF;
        while(r - l > 1) {
            __int128_t mid = (l + r) / 2;
            __int128_t del = min(w, min(w, (int)mid) * lb);
            __int128_t remain = h*w - line*del - ka*i - kb*mid;

            if(remain > 0) l = mid;
            else r = mid;
        }

        // cout << i << " " << i+r << endl;

        if(r != INF) chmin(ans, i + (int)r);
    }

    cout << ans << endl;
}

signed main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    solve();
    return 0;
}