#include <bits/stdc++.h>
#define int long long
#define MULTITEST false
using namespace std;
void solve () {
int N; cin >> N;
int T; cin >> T;
vector<int> A(2 * N);
for (int i = 0; i < N; i ++) {
int x;
cin >> x;
x %= T;
A[i] = x;
A[i + N] = x + T;
}
sort(A.begin(), A.end());
int l = 0;
int r = N - 1;
int m = (N >> 1);
int res = 0;
for (int i = l; i <= r; i ++)
res += abs(A[m] - A[i]);
do {
l ++;
m ++;
r ++;
int loc = 0;
for (int i = l; i <= r; i ++)
loc += abs(A[m] - A[i]);
res = min(res, loc);
} while (l != N);
cout << res << "\n";
}
signed main () {
ios_base::sync_with_stdio(false); cin.tie(NULL);
int T = 1;
if (MULTITEST) cin >> T;
for (int t = 0; t < T; t ++) solve();
}
