import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;

public class Main {
    static final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    static final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

    public static void main(String[] args) {
        try {
            IRunner runner = new Runner(br, bw);
            runner.run();
            runner.flush();

            br.close();
            bw.close();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}

class Runner implements IRunner {
    final IReader reader;
    final BufferedWriter bw;
    final StringBuilder sb = new StringBuilder();

    final int L, B, A, C, D;

    Runner(BufferedReader br, BufferedWriter bw) {
        this.reader = new Reader(br);
        this.bw = bw;

        try {
            int[] inputs = reader.lines().stream()
                    .mapToInt(Integer::parseInt)
                    .toArray();
            L = inputs[0];
            A = inputs[1];
            B = inputs[2];
            C = inputs[3];
            D = inputs[4];
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void flush() {
        try {
            bw.write(sb.toString());
            bw.flush();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void run() {
        int nDaysA = A / C + (A % C == 0 ? 0 : 1);
        int nDaysB = B / D + (B % D == 0 ? 0 : 1);
        sb.append(L - Math.max(nDaysA, nDaysB)).append("\n");
    }
}

interface IRunner {
    void run();

    void flush();
}

class Reader implements IReader {
    private BufferedReader br;

    public Reader(BufferedReader br) {
        this.br = br;
    }

    @Override
    public void skipLine() throws IOException {
        br.readLine();
    }

    @Override
    public int[] readInts() throws IOException {
        String[] tokens = br.readLine().split(" ");
        int[] ints = new int[tokens.length];
        for (int i = 0; i < tokens.length; ++i) {
            ints[i] = Integer.parseInt(tokens[i]);
        }
        return ints;
    }

    @Override
    public List<Integer> readIntegers() throws IOException {
        return Arrays.stream(readInts()).boxed().collect(Collectors.toList());
    }

    @Override
    public List<String> lines() throws IOException {
        return br.lines().collect(Collectors.toList());
    }
}

interface IReader {
    void skipLine() throws IOException;

    List<Integer> readIntegers() throws IOException;

    int[] readInts() throws IOException;

    List<String> lines() throws IOException;
}