#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
const int INF = 1e9;
const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A& a, const B& b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A& a, const B& b) { if (a > b) { a = b; return true; } return false; }

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	long long h, w, la, lb, ka, kb;
	cin >> h >> w >> la >> lb >> ka >> kb;
	long long ans = LINF;
	rep(i, h + w + 1) {
		long long ng = -1;
		long long ok = INF + 1;
		while (1 < abs(ok - ng)) {
			long long mid = (ng + ok) / 2;
			auto check = [&]() {
				long long val = 0;
				long long x = min(w, mid * lb);
				long long y = min(h, i * la);
				val += x * y;
				val += ka * i;
				val += mid * kb;
				return val >= h * w;
			};
			if (check()) ok = mid;
			else ng = mid;
		}
		chmin(ans, ok + i);
	}
	cout << ans << endl;
	return 0;
}