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E. Radio stations
time limit per test
2 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

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) ≥ |xi - xj|.

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

Find the number of bad pairs of radio stations.

Input

The first line contains two integers n and k (1 ≤ n ≤ 105, 0 ≤ k ≤ 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 ≤ xi, ri ≤ 109, 1 ≤ fi ≤ 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

Output the number of bad pairs of radio stations.

Examples
Input
3 2
1 3 10
3 2 5
4 10 8
Output
1
Input
3 3
1 3 10
3 2 5
4 10 8
Output
2
Input
5 1
1 3 2
2 2 4
3 2 1
4 2 1
5 3 3
Output
2
Input
5 1
1 5 2
2 5 4
3 5 1
4 5 1
5 5 3
Output
5