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.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class A289 {
  static FastScanner in;
  static FastWriter out;
  
  public static void main(String[] args) throws IOException {
    in = new FastScanner(System.in);
    out = new FastWriter(System.out);
    
    int n = in.nextInt();
    int k = in.nextInt();
    
    int val = 0;
    for (int i = 0; i < n; i++) {
      int l = in.nextInt();
      int r = in.nextInt();
      int cnt = r - l + 1;
      val += cnt;
      val %= k;
    }
    
    if (val == 0) {
      out.println(0);
    } else {
      out.println(k - val);
    }
    out.close();
  }
  
  static class FastScanner {
    BufferedReader br;
    StringTokenizer st;
    
    public FastScanner(InputStream in) {
      br = new BufferedReader(new InputStreamReader(in));
      st = new StringTokenizer("");
    }
    
    public FastScanner(File f) throws IOException {
      br = new BufferedReader(new FileReader(f));
      st = new StringTokenizer("");
    }
    
    public int nextInt() throws IOException {
      return Integer.parseInt(next());
    }
    
    public long nextLong() throws IOException {
      return Long.parseLong(next());
    }
    
    public double nextDouble() throws IOException {
      return Double.parseDouble(next());
    }
    
    public String next() throws IOException {
      if (st.hasMoreTokens()) return st.nextToken();
      st = new StringTokenizer(br.readLine());
      return next();
    }
  }
  
  static class FastWriter extends PrintWriter {
    public FastWriter(OutputStream out) throws IOException {
      super(new BufferedWriter(new OutputStreamWriter(out)));
    }
    
    public FastWriter(File f) throws IOException {
      super(new BufferedWriter(new FileWriter(f)));
    }
  }
}
