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.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.util.*;

public class Main implements Runnable {
	private boolean _READ_FROM_FILE = false; //System.getSecurityManager() == null; //System.getProperty("ONLINE_JUDGE") == null;
	private boolean _WRITE_TO_FILE = false;
	static final String _TASK_ID = "in";
	static final String _IN_FILE = _TASK_ID + ".in";
	static final String _OUT_FILE = _TASK_ID + ".out";
	BufferedReader reader;
	StringTokenizer tokenizer;
	
	class Target implements Comparable<Target>{
		long x, y, t;
		double p;
		public Target(long x, long y, long t, double p) {
			this.x = x;
			this.y = y;
			this.t = t;
			this.p = p;
		}
		public int compareTo(Target o) {
			if (t != o.t) return (int)(t - o.t);
			if (x != o.x) return (int)(x - o.x);
			return (int)(y - o.y);
		}
	}

	private void core() throws Exception {
		int n = nextInt();
		Target[] a = new Target[n];
		for (int i = 0; i < a.length; i++) {
			a[i] = new Target(nextLong(), nextLong(), nextLong(), nextDouble());
		}
		Arrays.sort(a);
		double[] best = new double[n];
		for (int i = 0; i < best.length; i++) {
			best[i] = Math.max(best[i], a[i].p);
			for (int j = i + 1; j < best.length; j++) {
				long len = sqr(a[i].x - a[j].x) + sqr(a[i].y - a[j].y);
				long time = sqr(a[i].t - a[j].t);
				if (len <= time)
					best[j] = Math.max(best[j], best[i] + a[j].p);
			}
		}
		double res = best[0];
		for (double d : best) {
			res = Math.max(res, d);
		}
		System.out.printf("%.7f\n", res);
	}
	private long sqr(long l) {
		return l*l;
	}
	void debug(Object...os) {
		System.out.println(Arrays.deepToString(os));
	}
	//--------------------- IO stuffs ---------------------
    public static void main(String[] args) throws InterruptedException {
        Thread thread = new Thread(new Main());
        thread.start();
        thread.join();
    }
	public void run() {
        try {
        	reader = new BufferedReader(_READ_FROM_FILE ? new FileReader(_IN_FILE) : new InputStreamReader(System.in));
        	System.setOut(new PrintStream(new BufferedOutputStream(_WRITE_TO_FILE ? new FileOutputStream(_OUT_FILE) : System.out)));
            tokenizer = new StringTokenizer("");
            core();
            reader.close();
            System.out.flush();
            System.out.close();
            System.exit(0);
        } catch (Exception e) {
        	System.out.flush();
            e.printStackTrace();
            System.exit(1);
        }
    }
    int nextInt() throws Exception {
        return Integer.parseInt(nextToken());
    }
    long nextLong() throws Exception {
        return Long.parseLong(nextToken());
    }
    double nextDouble() throws Exception {
        return Double.parseDouble(nextToken());
    }
    String nextToken() throws Exception {
        while (!tokenizer.hasMoreTokens())
			tokenizer = new StringTokenizer(reader.readLine());
        return tokenizer.nextToken();
    }
    boolean nextIsAvailable() throws Exception {
    	while (!tokenizer.hasMoreElements()) {
    		String line = reader.readLine();
    		if (line == null) return false;
    		tokenizer = new StringTokenizer(line);
    	}
    	return true;
    }
}