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

He has a set that consists of n integer segments: [l1; r1], [l2; r2], ..., [ln; rn]. 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 [l1; r1], [l2; r2], ..., [ln; rn] is the number of integers x, such that there is integer j, for which the following inequality holds, lj ≤ x ≤ rj.

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 ≤ 105). Each of the following n lines contain a segment as a pair of integers li and ri ( - 105 ≤ li ≤ ri ≤ 105), 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(ri, rj) < max(li, lj).

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
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.io.*;
import java.math.*;
import java.text.*;
import java.util.*;

/*
		br = new BufferedReader(new FileReader("input.txt"));
		pw = new PrintWriter(new BufferedWriter(new FileWriter("output.txt")));
		br = new BufferedReader(new InputStreamReader(System.in));
		pw = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));

 */

public class Main {
	private static BufferedReader br;
	private static StringTokenizer st;
	private static PrintWriter pw;

	static int[] dx = new int[]{-1,0,1,0};
	static int[] dy = new int[]{0,1,0,-1};

	public static void main(String[] args) throws IOException	{
		br = new BufferedReader(new InputStreamReader(System.in));
		pw = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
		//int qq = 1;
		int qq = Integer.MAX_VALUE;
		//int qq = readInt();
		for(int casenum = 1; casenum <= qq; casenum++)	{
			int n = readInt();
			int k = readInt();
			int ret = 0;
			while(n-- > 0)	{
				ret += -readInt() + readInt() + 1;
				ret %= k;
			}
			pw.println((k-ret)%k);
		}
		pw.close();
	}

	private static void exitImmediately()	{
		pw.close();
		System.exit(0);
	}

	private static long readLong() throws IOException	{
		return Long.parseLong(nextToken());
	}

	private static double readDouble() throws IOException	{
		return Double.parseDouble(nextToken());
	}

	private static int readInt() throws IOException	{
		return Integer.parseInt(nextToken());
	}

	private static String nextToken() throws IOException	{
		while(st == null || !st.hasMoreTokens())	{
			if(!br.ready())	{
				exitImmediately();
			}
			st = new StringTokenizer(br.readLine().trim());
		}
		return st.nextToken();
	}
}
