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.StringTokenizer;

public class Contest {
    void solve() throws IOException {
        int n = getInt();
        int k = getInt();
        long total = 0;
        for(int i = 0; i < n; ++i){
            int l = getInt();
            int r = getInt();
            total += r - l + 1;
        }
        if(total % k == 0)System.out.println(0);
        else System.out.println((k - (total % k)) % k);
    }

    BufferedReader bufferedReader;
    PrintWriter output;
    StringTokenizer tokenizer;

    public static void main(String[] args) throws IOException {
        Contest contest = new Contest();
        contest.run();
    }

    public String nextToken() throws IOException {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            tokenizer = new StringTokenizer(bufferedReader.readLine());
        }
        return tokenizer.nextToken();
    }

    public int getInt() throws IOException {
        return Integer.parseInt(nextToken());
    }

    public long getLong() throws IOException {
        return Long.parseLong(nextToken());
    }

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

    void run() throws IOException {
        bufferedReader = new BufferedReader(new InputStreamReader(System.in));
        output = new PrintWriter(System.out);
        solve();
    }
}
