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.FileInputStream;
import java.io.IOException;
import java.io.PrintStream;
import java.util.Scanner;


public class Codeforces {

    /**
     * @param args
     */
     private static MyScanner in;
        private static PrintStream out;

        public static void main(String[] args) throws IOException {
            out = System.out;
            boolean usingFileForIO = false;
            if (usingFileForIO) {
                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);
        }

        /**
         * 
         * @author wangchun
         *
         */
        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();
            }
        }
}
