import java.io.*;
import java.util.*;
import java.util.stream.*;

public class Main {
    static final int MOD = 998244353;
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        long h = sc.nextInt();
        long w = sc.nextInt();
        long total = h * w;
        long la = sc.nextInt();
        long lb = sc.nextInt();
        long ka = sc.nextInt();
        long kb = sc.nextInt();
        long ans = h + w;
        for (long i = 0; i < h + w; i++) {
            if (i * ka >= total) {
                ans = Math.min(ans, i);
                break;
            }
            long left = 0;
            long right = h + w;
            while (right - left > 1) {
                long m = (left + right) / 2;
                if (Math.min(h, la * i) * Math.min(w, lb * m) + ka * i + kb * m >= total) {
                    right = m;
                } else {
                    left = m;
                }
                ans = Math.min(ans, i + right);
            }
        }
        System.out.println(ans);
    }
}
class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}