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.io.*;
import java.io.ObjectInputStream.GetField;
import java.math.*;
import java.text.*;
import java.util.*;

//Codeforces
public class MainCodeforces1 {
	private static MyScanner in;
	private static PrintStream out;

	public static void main(String[] args) throws IOException {
		// helpers for input/output
		boolean LOCAL_TEST = false;// change to false before submitting
		out = System.out;
		if (LOCAL_TEST) {
			in = new MyScanner("E:\\zin2.txt");
		}
		else {
			boolean usingFileForIO = false;
			if (usingFileForIO) {
				// using input.txt and output.txt as I/O
				in = new MyScanner("input.txt");
				out = new PrintStream("output.txt");
			}
			else {
				in = new MyScanner();
				out = System.out;
			}
		}

		solve();
	}

	private static void solve() throws IOException
	{
		int n = in.nextInt();
		int k = in.nextInt();
		int cnt = 0;
		for (int i = 0; i < n; i++) {
			int l = in.nextInt();
			int r = in.nextInt();
			cnt += r - l + 1;
		}
		int z;
		if (cnt % k == 0) {
			z = 0;
		}
		else {
			z = k - (cnt % k);
		}
		out.println(z);
	}

	// =====================================
	static class MyScanner {
		Scanner inp = null;

		public MyScanner() throws IOException
		{
			inp = new Scanner(System.in);
		}

		public MyScanner(String inputFile) throws IOException {
			inp = new Scanner(new FileInputStream(inputFile));
		}

		public int nextInt() throws IOException {
			return inp.nextInt();
		}

		public long nextLong() throws IOException {
			return inp.nextLong();
		}

		public double nextDouble() throws IOException {
			return inp.nextDouble();
		}

		public String nextString() throws IOException {
			return inp.next();
		}

	}

}