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

public class input2 {
    public static int id[] = new int[60005];

    public static void init() {
        for (int i = 0; i < 60005; i++) {
            id[i] = i;
        }
    }

    public static int root(int x) {
        while (id[x] != x) {
            id[x] = id[id[x]];
            x = id[x];
        }
        return x;
    }

    public static void union(int x, int y) {
        int p = root(x);
        int q = root(y);
        id[p] = id[q];
    }

    public static long kruskal(ArrayList<ArrayList<Integer>> A) {
        long min = 0;
        Collections.sort(A, new sort());
        int x, y;
        int cost = 0;
        for (int i = 0; i < A.size(); i++) {
            x = A.get(i).get(0);
            y = A.get(i).get(1);
            cost = A.get(i).get(2);
            System.out.println("I am cost : " + cost);
            System.out.println("I am root x : " + x + " " + root(x));
            System.out.println("I am root y : " + root(y));
            if (root(x) != root(y)) {
                min += cost;
                union(x, y);
            }
        }
        return min;
    }

    public static void main(String args[]) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine());
        int n = Integer.parseInt(st.nextToken());
        int m = Integer.parseInt(st.nextToken());
        long v = 0;
        for(int i=0;i<n;i++){
            st = new StringTokenizer(br.readLine());
            long a = Long.parseLong(st.nextToken());
            long b = Long.parseLong(st.nextToken());
            long dif = b-a+1;
            v+=dif;
        }
        long mod = v%m;
        if(mod == 0){
            System.out.println(0);
        }
        else{
            System.out.println(m-mod);
        }
    }

    static class sort implements Comparator<ArrayList<Integer>> {

        @Override
        public int compare(ArrayList<Integer> o1, ArrayList<Integer> o2) {
            int c = o1.get(2).compareTo(o2.get(2));
            return c;
        }

    }
}