One day three best friends Petya, Vasya and Tonya decided to form a team and take part in programming contests. Participants are usually offered several problems during programming contests. Long before the start the friends decided that they will implement a problem if at least two of them are sure about the solution. Otherwise, the friends won't write the problem's solution.

This contest offers n problems to the participants. For each problem we know, which friend is sure about the solution. Help the friends find the number of problems for which they will write a solution.

Input

The first input line contains a single integer n (1 ≤ n ≤ 1000) — the number of problems in the contest. Then n lines contain three integers each, each integer is either 0 or 1. If the first number in the line equals 1, then Petya is sure about the problem's solution, otherwise he isn't sure. The second number shows Vasya's view on the solution, the third number shows Tonya's view. The numbers on the lines are separated by spaces.

Output

Print a single integer — the number of problems the friends will implement on the contest.

Examples

Input

3
1 1 0
1 1 1
1 0 0


Output

2


Input

2
1 0 0
0 1 1


Output

1

Note

In the first sample Petya and Vasya are sure that they know how to solve the first problem and all three of them know how to solve the second problem. That means that they will write solutions for these problems. Only Petya is sure about the solution for the third problem, but that isn't enough, so the friends won't take it. 

In the second sample the friends will only implement the second problem, as Vasya and Tonya are sure about the solution.
/*
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 is only distributed under the terms of a separate license agreement
 with NetCracker.
 Use of the software is governed by the terms of the license agreement.
 Any use of this software not in accordance with the license agreement
 is expressly prohibited by law, and may result in severe civil
 and criminal penalties.

 Copyright (c) 1995-2014 NetCracker Technology Corp.

 All Rights Reserved.

*/
/*
 * Copyright 1995-2014 by NetCracker Technology Corp.,
 * University Office Park III
 * 95 Sawyer Road
 * Waltham, MA 02453
 * United States of America
 * All rights reserved.
 */

import java.util.Arrays;
import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

/**
 * @author EUZI0511
 */
public class T implements Runnable
{
    public static void main(String[] args)
    {
        new Thread(new T()).start();
    }

    @Override
    public void run()
    {
        Scanner scanner = new Scanner(System.in);

        int n = scanner.nextInt();

        int result = 0;

        for (int i = 0; i < n; i++)
        {
            int a = scanner.nextInt(), b = scanner.nextInt(), c = scanner.nextInt();
            if (a + b + c >= 2)
                result++;
        }

        System.out.println(result);
    }

    String atoi(int n)
    {
        StringBuilder sb = new StringBuilder();

        if (n < 0)
            sb.append('-');
        n = Math.abs(n);

        int q = 1;
        while (q <= n)
        {
            q *= 10;
        }
        q /= 10;

        while (q > 0)
        {
            int d = n / q;
            n = n % q;
            sb.append(d);
            q /= 10;
        }
        return sb.toString();
    }
}
/*
 WITHOUT LIMITING THE FOREGOING, COPYING, REPRODUCTION, REDISTRIBUTION,
 REVERSE ENGINEERING, DISASSEMBLY, DECOMPILATION OR MODIFICATION
 OF THE SOFTWARE IS EXPRESSLY PROHIBITED, UNLESS SUCH COPYING,
 REPRODUCTION, REDISTRIBUTION, REVERSE ENGINEERING, DISASSEMBLY,
 DECOMPILATION OR MODIFICATION IS EXPRESSLY PERMITTED BY THE LICENSE
 AGREEMENT WITH NETCRACKER.

 THIS SOFTWARE IS WARRANTED, IF AT ALL, ONLY AS EXPRESSLY PROVIDED IN
 THE TERMS OF THE LICENSE AGREEMENT, EXCEPT AS WARRANTED IN THE
 LICENSE AGREEMENT, NETCRACKER HEREBY DISCLAIMS ALL WARRANTIES AND
 CONDITIONS WITH REGARD TO THE SOFTWARE, WHETHER EXPRESS, IMPLIED
 OR STATUTORY, INCLUDING WITHOUT LIMITATION ALL WARRANTIES AND
 CONDITIONS OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE,
 TITLE AND NON-INFRINGEMENT.

 Copyright (c) 1995-2014 NetCracker Technology Corp.

 All Rights Reserved.
*/