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.System.exit;
    import java.util.ArrayList;
    import java.util.LinkedList;
    import java.util.List;
    import java.util.Scanner;
    import java.util.*;
    /**
     *
     * @author abdelmagied
     */
    import java.util.ArrayList;
    import java.util.Collections;
    import java.util.Comparator;
    import java.util.HashMap;
    import java.util.LinkedList;
    import java.util.List;
    import java.util.Map;
    import java.util.Scanner;
    import javafx.scene.Node;

    /**
     *
     * @author abdelmagied
     */
    public class JavaApplication1 { 
        /**
         * @param args the command line arguments
       */
       public static void main(String[] args){ 
          Scanner sc = new Scanner(System.in);
          
         int n = sc.nextInt() , k = sc.nextInt();
         int sum = 0;
         
         for(int i = 0 ; i < n ; i++){
             int from = sc.nextInt() , to = sc.nextInt();
             sum += (to - from) + 1;            
         }
         
         int ans = (sum % k==0)?0:k - (sum % k);
         
         System.out.println(ans);
       }
}



