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 static java.lang.Double.*;
import static java.lang.Integer.*;
import static java.lang.Long.*;
import static java.lang.System.*;

import java.io.*;
import java.util.*;

public class Main {
	static void solve() throws IOException {
		int n = nextInt();
		int k = nextInt();
		int cnt = 0;
		for (int i = 0; i < n; i++) {
			int l = nextInt();
			int r = nextInt();
			cnt += r - l + 1;
		}
		int ans = (k - cnt % k) % k;
		out.println(ans);
	}
	
	public static void main(String[] args) throws IOException {
		try {
			br = new BufferedReader(new FileReader("input"));
			out = new PrintWriter(("output"));
		} catch (FileNotFoundException e) {
			br = new BufferedReader(new InputStreamReader(in));
			out = new PrintWriter(new OutputStreamWriter(System.out));
		}
		solve();
		br.close();
		out.close();
	}
	
	static BufferedReader br;
	static PrintWriter out;
	static StringTokenizer tok;
	
	static int nextInt() throws IOException {
		return parseInt(next());
	}
	
	static long nextLong() throws IOException {
		return parseLong(next());
	}
	
	static double nextDouble() throws IOException {
		return parseDouble(next());
	}
	
	static String next() throws IOException {
		while (tok == null || !tok.hasMoreTokens()) {
			tok = new StringTokenizer(br.readLine());
		}
		return tok.nextToken();
	}
}