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.util.StringTokenizer;
import java.io.PrintWriter;



public class A {


	public static void main(String[]args)throws IOException {
		FastReader sc = new FastReader();
		PrintWriter out = new PrintWriter(System.out);
		int n = sc.nextInt();
		int k = sc.nextInt();
		int diff = 0;
		while (n-- > 0) {
			int i = sc.nextInt(), j = sc.nextInt();
			diff += j - i + 1;
		}

		int m = (diff + k - 1) / k;
		out.println(k * m - diff);
		out.close();
	}





// public static euclidTriplet euclidExtended(int a, int b) {
// 	if (b == 0)
// 		return new euclidTriplet(1, 0, a);

// 	euclidTriplet ans = euclidExtended(b, a % b);

// 	return new euclidTriplet(ans.y, ans.x - (a / b) * ans.y, ans.gcd);
// }


// public static int  gcd(int a, int b) {
// 	if (a == 0)
// 		return b;

// 	return gcd(b % a, a);
// }

}

// class euclidTriplet {
// 	int x, y, gcd;
// 	euclidTriplet(int x, int y, int gcd) {
// 		this.x = x;
// 		this.y = y;
// 		this.gcd = gcd;
// 	}
// }


// class comp implements Comparator<long []> {
// 	public int compare(long [] arr1, long[] arr2) {
// 		if ((2 * arr2[0] + arr2[1]) > (2 * arr1[0] + arr1[1]))
// 			return 1;

// 		else
// 			return -1;
// 	}
// }


class FastReader {

	BufferedReader br;
	StringTokenizer st;

	public FastReader() {
		br = new BufferedReader(new InputStreamReader(System.in));
	}

	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());
	}

	int [] nextIntArray(int n) {
		int [] arr = new int[n];
		for (int i = 0; i < n; i++)
			arr[i] = nextInt();

		return arr;

	}


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

	long [] nextLongArray(int n) {
		long [] arr = new long[n];
		for (int i = 0; i < n; i++)
			arr[i] = nextLong();

		return arr;

	}

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

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

}