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.*;
import java.math.*;

public class GGWPLivaem implements Runnable{
    boolean withFiles = false;
    class cc implements Comparable<cc>{
        public int x, y;
        cc(int x, int y) {
            this.x = x;
            this.y = y;
        }
        public int compareTo(cc other) {
            if (this.x == other.x) {
                return Integer.compare(this.y, other.y);
            }
            return Integer.compare(this.x, other.x);
        }
    }

    private void solve() throws IOException {
        int n = in.nextInt(), k = in.nextInt();
        long ss = 0;
        for (int i = 1; i <= n; ++i) {
            int a = in.nextInt(), b = in.nextInt();
            ss += b - a + 1;
        }
        out.printf("%d", (k - ss % k) % k);
    }

    private static class FastScanner{
        private BufferedReader reader;
        private StringTokenizer tokenizer;
        String cache;
        int cur;

        FastScanner(Reader r) throws IOException{
            reader = new BufferedReader(r);
            tokenizer = new StringTokenizer("");
            cache = null;
            cur = 0;
        }

        public boolean hasNext(){
            if (cache != null && cur < cache.length())
                return true;
            try {
                while (!tokenizer.hasMoreTokens()){
                    String line = reader.readLine();
                    if (line == null)
                        return false;
                    tokenizer = new StringTokenizer(line);
                }
                cache = tokenizer.nextToken();
                cur = 0;
            }
            catch(IOException e) {
                return false;
            }
            return true;
        }

        public char nextChar() throws IOException{
            if (!hasNext())
                throw new EOFException();
            return cache.charAt(cur++);
        }

        public String next() throws IOException{
            if (!hasNext())
                throw new EOFException();
            String result = (cur == 0) ? cache : cache.substring(cur);
            cache = null;
            return result;
        }

        public int nextInt() throws IOException{
            return Integer.parseInt(this.next());
        }

        public long nextLong() throws IOException{
            return Long.parseLong(this.next());
        }

        public double nextDouble() throws IOException{
            return Double.parseDouble(this.next());
        }

        public BigInteger nextBigInteger() throws IOException{
            return new BigInteger(this.next());
        }

        public void close() throws IOException{
            reader.close();
            tokenizer = new StringTokenizer("");
        }
    }


    public static void main(String args[]) throws IOException{
        new Thread(null, new GGWPLivaem(), "Thread #228", 64 * 1024 * 1024).start();
    }

    public void run(){
        try{
            if (withFiles) {
                in = new FastScanner(new FileReader("input.txt"));
                out = new PrintWriter(new FileWriter("output.txt"));
            }
            else {
                in = new FastScanner(new InputStreamReader(System.in));
                out = new PrintWriter(System.out);
            }
            solve();
            in.close();
            out.close();
        }
        catch(IOException e){
            e.printStackTrace();
        }
    }

    FastScanner in;
    PrintWriter out;
}
