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.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.StreamTokenizer;


public class A {
	static PrintWriter out;
	static StreamTokenizer st;
	static BufferedReader bf;
	public static void main(String[] args) throws IOException {
		bf = new BufferedReader(new InputStreamReader(System.in));
		st = new StreamTokenizer(bf);
		out = new PrintWriter(new OutputStreamWriter(System.out));
		int n = nextInt();
		int k = nextInt();
		int cnt = 0;
		int l,r;
		for (int i = 0; i < n; i++) {
			l = nextInt();
			r = nextInt();
			cnt += r-l+1;
		}
		if (cnt%k == 0){
			System.out.println(0);
		}else{
			System.out.println((cnt/k+1)*k-cnt);
		}
		
		out.close();
		
	}
	private static String nextLine() throws IOException {
		return bf.readLine().trim();
	}
	private static double nextDouble() throws IOException{
		st.nextToken();
		return st.nval;
	}
	private static long nextLong()  throws IOException{
		st.nextToken();
		return (long) st.nval;
	}
	private static int nextInt() throws IOException {
		st.nextToken();
		return (int) st.nval;
	}

}
