1981.Radio stations

Time Limit: 1s Memory Limit: 256MB

In the lattice points of the coordinate line there are n radio stations, the i-th of which is described by three integers:
xi - the coordinate of the i-th station on the line, ri - the broadcasting range of the i-th station, fi - the broadcasting frequency of the i-th station.
We will say that two radio stations with numbers i and j reach each other, if the broadcasting range of each of them is more or equal to the distance between them. In other words min(ri,rj) \ge |xi-xj|.

Let's call a pair of radio stations (i,j) bad if i \lt j, stations i and j reach each other and they are close in frequency, that is, |fi-fj| \le k.

Find the number of bad pairs of radio stations.

Input Format(From the terminal/stdin)

The first line contains two integers n and k (1 \le n \le 105, 0 \le k \le 10) - the number of radio stations and the maximum difference in the frequencies for the pair of stations that reach each other to be considered bad.

In the next n lines follow the descriptions of radio stations. Each line contains three integers xi, ri and fi (1 \le xi,ri \le 109, 1 \le fi \le 104) - the coordinate of the i-th radio station, it's broadcasting range and it's broadcasting frequency. No two radio stations will share a coordinate.

Output Format(To the terminal/stdout)

Output the number of bad pairs of radio stations.

Sample Input 1

Copy
3 2
1 3 10
3 2 5
4 10 8
 · \n
 · ·  \n
 · · \n
 ·  · \n

Sample Output 1

Copy
1
 \n

Sample Input 2

Copy
3 3
1 3 10
3 2 5
4 10 8
 · \n
 · ·  \n
 · · \n
 ·  · \n

Sample Output 2

Copy
2
 \n

Sample Input 3

Copy
5 1
1 3 2
2 2 4
3 2 1
4 2 1
5 3 3
 · \n
 · · \n
 · · \n
 · · \n
 · · \n
 · · \n

Sample Output 3

Copy
2
 \n

Sample Input 4

Copy
5 1
1 5 2
2 5 4
3 5 1
4 5 1
5 5 3
 · \n
 · · \n
 · · \n
 · · \n
 · · \n
 · · \n

Sample Output 4

Copy
5
 \n

Submit

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