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.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class A {

	private static StringTokenizer tokenizer;
    private static BufferedReader bf;
    private static PrintWriter out;
    
	private static int nextInt() throws IOException {
    	return Integer.parseInt(nextToken());
    }
    
    @SuppressWarnings("unused")
	private static long nextLong() throws IOException {
    	return Long.parseLong(nextToken());
    }
    
    private static String nextToken() throws IOException {
    	while(tokenizer == null || !tokenizer.hasMoreTokens()) {
    		tokenizer = new StringTokenizer(bf.readLine());
    	}
    	return tokenizer.nextToken();
    }
    
	public static void main(String[] args) throws IOException {
		
		bf = new BufferedReader(new InputStreamReader(System.in));
    	tokenizer = null;
    	out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
    	int n = nextInt(); int k = nextInt();
    	int res = 0;
    	for(int i = 1; i <= n; i++) {
    		int l = nextInt(); int r = nextInt();
    		res += (r-l+1);
    	}
    	res = k*((res+k-1)/k) - res;
    	out.println(res);
    	out.close();
	}

}