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.util.*;

public class Solution {
    public static void main (String[] args) throws IOException {
        boolean online = "true".equals(System.getProperty("ONLINE_JUDGE"));
        if (online) {
            in = new InputReader(new InputStreamReader(System.in));
            out = new PrintWriter(System.out);
        }
        else {
            in = new InputReader(new FileReader("input.txt"));
            out = new PrintWriter(new File("output.txt"));
        }
        
        new Solution().run();
        
        out.close();
    }
    
    private void run () {
        int n = in.nextInt(),
            k = in.nextInt();
        int sum = 0;
        for (int i = 0; i < n; ++i) {
            int l = in.nextInt(),
                r = in.nextInt();
            sum += r - l + 1;
        }
        out.println((k - sum % k) % k);
    }
    
    private static InputReader in;
    private static PrintWriter out;
}

class InputReader {
    public InputReader (Reader r) {
        buff = new BufferedReader(r);
        try {
            str = new StringTokenizer(buff.readLine());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    
    public String next () {
        while (!str.hasMoreTokens())
            try {
                str = new StringTokenizer(buff.readLine());
            } catch (IOException e) {
                e.printStackTrace();
            }
        return str.nextToken();
    }
    
    public int nextInt () {
        return Integer.parseInt(this.next());
    }
    
    public long nextLong () {
        return Long.parseLong(this.next());
    }
    
    private static BufferedReader buff;
    private static StringTokenizer str;
}