Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ACM-ICPC mode for virtual contests.
If you've seen these problems, a virtual contest is not for you - solve these problems in the archive.
If you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.
Never use someone else's code, read the tutorials or communicate with other person during a virtual contest.

No tag edit access

B. Gleb And Pizza

time limit per test

2 secondsmemory limit per test

256 megabytesinput

standard inputoutput

standard outputGleb ordered pizza home. When the courier delivered the pizza, he was very upset, because several pieces of sausage lay on the crust, and he does not really like the crust.

The pizza is a circle of radius *r* and center at the origin. Pizza consists of the main part — circle of radius *r* - *d* with center at the origin, and crust around the main part of the width *d*. Pieces of sausage are also circles. The radius of the *i* -th piece of the sausage is *r*_{i}, and the center is given as a pair (*x*_{i}, *y*_{i}).

Gleb asks you to help determine the number of pieces of sausage caught on the crust. A piece of sausage got on the crust, if it completely lies on the crust.

Input

First string contains two integer numbers *r* and *d* (0 ≤ *d* < *r* ≤ 500) — the radius of pizza and the width of crust.

Next line contains one integer number *n* — the number of pieces of sausage (1 ≤ *n* ≤ 10^{5}).

Each of next *n* lines contains three integer numbers *x*_{i}, *y*_{i} and *r*_{i} ( - 500 ≤ *x*_{i}, *y*_{i} ≤ 500, 0 ≤ *r*_{i} ≤ 500), where *x*_{i} and *y*_{i} are coordinates of the center of *i*-th peace of sausage, *r*_{i} — radius of *i*-th peace of sausage.

Output

Output the number of pieces of sausage that lay on the crust.

Examples

Input

8 4

7

7 8 1

-7 3 2

0 2 1

0 -2 2

-3 -3 1

0 6 2

5 3 1

Output

2

Input

10 8

4

0 0 9

0 0 10

1 0 1

1 0 2

Output

0

Note

Below is a picture explaining the first example. Circles of green color denote pieces of sausage lying on the crust.

Codeforces (c) Copyright 2010-2017 Mike Mirzayanov

The only programming contests Web 2.0 platform

Server time: Sep/23/2017 01:24:19 (c3).

Desktop version, switch to mobile version.

User lists

Name |
---|