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.*;

/*
* @author: Ramanqul
* */
public class Main {
    private static boolean USE_TEST_CASES = false;

    private static void solve(MyScanner in, PrintWriter out) {
        int n = in.nextInt();
        int k = in.nextInt();

        int a[][] = new int[n][2];

        for (int i=0;i<n;i++) {
            a[i][0] = in.nextInt();
            a[i][1] = in.nextInt();
        }

        long sum = 0;
        for (int i=0;i<n;i++) {
            int x = a[i][1] - a[i][0] + 1;
            sum += x;
        }

        long d = sum % k;
        long ans = (k-sum%k)%k;

        out.println(ans);

    }

    public static void main(String[] args) {
        MyScanner sc = new MyScanner();
        PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out));
        int t = 1;

        if (USE_TEST_CASES) {
            t = sc.nextInt();
        }

        for (int i=0;i<t;i++) {
            solve(sc, out);
        }
        out.close();
    }

    private static class Pair<A,B> {
        public A first;
        public B second;
        public Pair(A first, B second) {
            this.first = first;
            this.second = second;
        }
    }

    private static class Triple<A,B,C> {
        public A first;
        public B second;
        public C third;

        public Triple(A first, B second, C third) {
            this.first = first;
            this.second = second;
            this.third = third;
        }
    }

    private static class H {
        public static void readArray(MyScanner in, int a[], int n) {
            for (int i=0;i<n;i++) {
                a[i] = in.nextInt();
            }
        }

        public static boolean isUnique(int ... nums) {
            Set<Integer> s = new HashSet<>();
            for (int i:nums) {
                if (s.contains(i)) {
                    return false;
                }
                s.add(i);
            }

            return true;
        }


        public static Pair<Integer, Integer>[] readIntPairs(MyScanner in, int n) {
            Pair[] pairs = new Pair[n];
            for (int i=0;i<n;i++) {
                int x = in.nextInt();
                int y = in.nextInt();
                pairs[i] = new Pair<Integer, Integer>(x, y);
            }

            return pairs;
        }

        public static List<Integer> dfs(int start, List<Integer>[] adj) {
            boolean v[] = new boolean[adj.length+1];

            List<Integer> res = new ArrayList<>();

            Stack<Integer> st = new Stack<>();

            st.push(start);

            while (!st.isEmpty()) {
                int x = st.pop();
                if (!v[x]) {
                    res.add(x);
                    boolean allVisited = true;
                    for (int e: adj[x]) {
                        if (!v[e]) {
                            st.push(e);
                            allVisited = false;
                        }
                    }

                    if (allVisited) {
                        break;
                    }

                    v[x] = true;
                } else {
                    break;
                }
            }

            return res;
        }

        public static long gcd(long a, long b) {
            if (a == 0) {
                return b;
            }

            return gcd(b%a, a);
        }

        public static long lcm(long a, long b) {
            return (a * b) / gcd(a,b);
        }
    }

    private static class MyScanner {
        BufferedReader br;
        StringTokenizer st;

        public MyScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
        public MyScanner(InputStream is) {
            br = new BufferedReader(new InputStreamReader(is));
        }

        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        String nextLine(){
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }

    }
}