Problem: One warm and sunny day king Copa decided to visit the shooting gallery, located at the Central Park, and try to win the main prize — big pink plush panda. The king is not good at shooting, so he invited you to help him.

The shooting gallery is an infinite vertical plane with Cartesian coordinate system on it. The targets are points on this plane. Each target is described by it's coordinates xi, and yi, by the time of it's appearance ti and by the number pi, which gives the probability that Copa hits this target if he aims at it.

A target appears and disappears instantly, so Copa can hit the target only if at the moment ti his gun sight aimed at (xi, yi). Speed of movement of the gun sight on the plane is equal to 1. Copa knows all the information about the targets beforehand (remember, he is a king!). He wants to play in the optimal way, which maximizes the expected value of the amount of hit targets. He can aim at any target at the moment 0.

Input

The first line contains integer n (1 ≤ n ≤ 1000) — amount of targets in the shooting gallery. Then n lines follow, each describing one target. Each description consists of four numbers xi, yi, ti, pi (where xi, yi, ti — integers,  - 1000 ≤ xi, yi ≤ 1000, 0 ≤ ti ≤ 109, real number pi is given with no more than 6 digits after the decimal point, 0 ≤ pi ≤ 1). No two targets may be at the same point.

Output

Output the maximum expected value of the amount of targets that was shot by the king. Your answer will be accepted if it differs from the correct answer by not more than 10 - 6.

Examples

Input

1
0 0 0 0.5


Output

0.5000000000


Input

2
0 0 0 0.6
5 0 5 0.7


Output

1.3000000000

Solution (in JAVA):

Solution:
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.Arrays;
import java.util.Comparator;
import java.io.BufferedReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.StringTokenizer;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 * @author tohuuquan
 */
public class Main {
	public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		TaskC solver = new TaskC();
		solver.solve(1, in, out);
		out.close();
	}
}

class TaskC {
    final double eps = 1E-8;

    public void solve(int testNumber, InputReader in, PrintWriter out) {
        int n = in.nextInt();
        int[] x = new int[n];
        int[] y = new int[n];
        final int[] t = new int[n];
        double[] p = new double[n];
        for (int i = 0; i < n; ++i) {
            x[i] = in.nextInt();
            y[i] = in.nextInt();
            t[i] = in.nextInt();
            p[i] = in.nextDouble();
        }

        Integer[] id = new Integer[n];
        for (int i = 0; i < n; ++i) id[i] = i;
        Arrays.sort(id, new Comparator<Integer>() {
            public int compare(Integer o1, Integer o2) {
                return t[o1] - t[o2];
            }
        });

        double[] res = new double[n];
        for (int i = 0; i < n; ++i) {
            for (int j = i - 1; j >= 0; --j) {
                if (Math.hypot(x[id[i]] - x[id[j]], y[id[i]] - y[id[j]]) < t[id[i]] - t[id[j]] + eps)
                    res[id[i]] = Math.max(res[id[i]], res[id[j]]);
            }
            res[id[i]] += p[id[i]];
        }

        double result = 0;
        for (double value: res)
            result = Math.max(result, value);

        out.printf("%.10f", result);
    }
}

class InputReader {
    BufferedReader reader;
    StringTokenizer tokenizer;

    public InputReader(InputStream stream) {
        reader = new BufferedReader(new InputStreamReader(stream));
        tokenizer = null;
    }

    public String next() {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    }

    public int nextInt() {
        return Integer.parseInt(next());
    }

    public double nextDouble() {
        return Double.parseDouble(next());
    }
}