Package for this problem was not updated by the problem writer or Codeforces administration after we’ve upgraded the judging servers. To adjust the time limit constraint, solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then value 800 ms will be displayed and used to determine the verdict.

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

A. Polo the Penguin and Segments

time limit per test

2 secondsmemory limit per test

256 megabytesinput

standard inputoutput

standard outputLittle penguin Polo adores integer segments, that is, pairs of integers [*l*; *r*] (*l* ≤ *r*).

He has a set that consists of *n* integer segments: [*l*_{1}; *r*_{1}], [*l*_{2}; *r*_{2}], ..., [*l*_{n}; *r*_{n}]. We know that no two segments of this set intersect. In one move Polo can either widen any segment of the set 1 unit to the left or 1 unit to the right, that is transform [*l*; *r*] to either segment [*l* - 1; *r*], or to segment [*l*; *r* + 1].

The value of a set of segments that consists of *n* segments [*l*_{1}; *r*_{1}], [*l*_{2}; *r*_{2}], ..., [*l*_{n}; *r*_{n}] is the number of integers *x*, such that there is integer *j*, for which the following inequality holds, *l*_{j} ≤ *x* ≤ *r*_{j}.

Find the minimum number of moves needed to make the value of the set of Polo's segments divisible by *k*.

Input

The first line contains two integers *n* and *k* (1 ≤ *n*, *k* ≤ 10^{5}). Each of the following *n* lines contain a segment as a pair of integers *l*_{i} and *r*_{i} ( - 10^{5} ≤ *l*_{i} ≤ *r*_{i} ≤ 10^{5}), separated by a space.

It is guaranteed that no two segments intersect. In other words, for any two integers *i*, *j* (1 ≤ *i* < *j* ≤ *n*) the following inequality holds, *min*(*r*_{i}, *r*_{j}) < *max*(*l*_{i}, *l*_{j}).

Output

In a single line print a single integer — the answer to the problem.

Examples

Input

2 3

1 2

3 4

Output

2

Input

3 7

1 2

3 3

4 7

Output

0

Codeforces (c) Copyright 2010-2017 Mike Mirzayanov

The only programming contests Web 2.0 platform

Server time: Mar/24/2017 11:04:19 (c3).

Desktop version, switch to mobile version.
User lists

Name |
---|