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
def solve(res,n,k):
    tot = 0
    for i in res:
        tot += i[1]-i[0]+1
    count = 0
    while tot%k != 0:
        tot += 1
        count += 1
    return count

    
   


    

def main():
    n,k = list(map(int, input().split(" ")))
    # k= int(input())
    # n = int(input())

    # s = input()
    # a = list(map(int, input().split(" ")))
    # b = list(map(int, input().split(" ")))
    # c = list(map(int, input().split(" ")))
    res = []
    for _ in range(n):
       arr = list(map(int, input().split(" ")))
       res.append(arr)
    print(solve(res,n,k))
    # i = 0
    # inputpath = 'input.txt'
    # outPath = 'output.txt'
    # with open(inputpath) as fp:
    #     line = fp.readline()
    #     cnt = 1
    #     while line:
    #         if cnt == 1:
    #             i = int(line)
    #         else:
    #            arr = list(map(int, line.split(" ")))
    #            res.append(arr)  
    #         cnt += 1
    #         line = fp.readline()
    # s = solve(res,i)
    # with open(outPath, 'a') as out:
    #     out.write(str(s))


main()