#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ff first
#define ss second
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define ertunt return
const int MOD = 998244353;
#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
int main() {
ll n,t;
cin >> n >> t;
ll a[n];
vector<ll>v(t,0);
for(ll i = 0; i < n; i++){
cin >> a[i];
v[a[i]%t]++;
}
ll ans = 1e18;
for(ll i = 0; i < t; i++){
ll res = 0;
for(ll j = 0; j < t; j++){
ll x = min(t-abs(i-j),abs(i-j));
res+=x*v[j];
}
ans = min(ans,res);
}
cout << ans;
}
