import math
num,k = list(map(int, input().split(' ')))
count = 0
for i in (range(num)):
rang = list(map(int, input().split(' ')))
count += rang[1]-rang[0]+1
count = k* math.ceil(count/k) - count
print(count)#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include<cmath> //float result = pow(b,p) //trunc(10.25)=10 // floor(10.55)=10 // ceil(10.55)=11 //round(10.1)=10 , round(10.55)=11
#include <unordered_map> // unordered_map<int,int>mp;
using namespace std;
#define fast \
ios_base::sync_with_stdio(0); \
cin.tie(0); \
cout.tie(0);
// -842150451
// a=97 , z= 122 , A=65 ,Z=90
#include<set>
int main() {
//extern int arr [5] ;
//fast
int before=0 , after =0 ;
int n, k; cin >> n >> k;
for (int i = 0;i<n;i++) {
int l; cin >> l;
int r; cin >> r;
before += 1 + r - l;
}
for (int i = 0; true; i++) {
if ((after+before) % k == 0) {
break;
}
after++;
}
cout << after << endl;
}600C - Make Palindrome | 1669D - Colorful Stamp |
1669B - Triple | 1669A - Division |
1669H - Maximal AND | 1669E - 2-Letter Strings |
483A - Counterexample | 3C - Tic-tac-toe |
1669F - Eating Candies | 1323B - Count Subrectangles |
991C - Candies | 1463A - Dungeon |
1671D - Insert a Progression | 1671A - String Building |
1671B - Consecutive Points Segment | 1671C - Dolce Vita |
1669G - Fall Down | 4D - Mysterious Present |
1316B - String Modification | 1204A - BowWow and the Timetable |
508B - Anton and currency you all know | 1672A - Log Chopping |
300A - Array | 48D - Permutations |
677C - Vanya and Label | 1583B - Omkar and Heavenly Tree |
1703C - Cypher | 1511C - Yet Another Card Deck |
1698A - XOR Mixup | 1702E - Split Into Two Sets |