/*
differenciating slope??? not sure if it's an actual thing
*/
#include<bits/stdc++.h>
using namespace std;
#define int long long
int t, n, m, a[200005], ans, sum, slo;
vector< pair<int, pair<int, int> > > event;
//at most 3 each
signed main(){
	cin>>t;
	while(t--){
		cin>>n>>m;
		//when, and by how much
		sum = 0;
		slo = 0;
		ans = INT_MAX;
		while(event.size())event.pop_back();
		for(int i = 1; i <= n; i++){
			cin>>a[i];
		}
		for(int i = 1; i <= n; i++){
			int re = a[i] % m;
			int b1 = re;
			int b2;
			if(m % 2 == 0){
				if(re <= (m / 2))b2 = re + (m / 2);
				else b2 = re - (m / 2);	
			}else{
				if(re <= (m / 2))b2 = re + (m / 2);
				else b2 = re - (m / 2 + 1); 
			}
			//b1 and b2 are the two break points
			sum += min(re, m - re);
			//sum = the answer when x == 0 
			if(b1 > b2)slo += 1;
			else slo -= 1;
			//determines the inital slope, upwards or downwards
			if(m % 2 == 1){
				event.push_back({b2, {-1, i}});
				//reach b2, stay
				event.push_back({b2 + 1, {-1, i}});
				//start decreasing				
			}else{
				event.push_back({b2, {-2, i}});
				//start decreasing right away
			}
			event.push_back({b1, {2, i}});
			//reach the remainder itself, start growing again
		}
		sort(event.begin(), event.end());
		int la = 0;
		ans = sum;
		for(int i = 0; i < event.size(); i++){
			int tim = event[i].first;
			int val = event[i].second.first;
			int id = event[i].second.second;
			//tim = time of this event
			//val = how much is changed
			//id = who's changed. not really necessary
			sum += (tim - la) * slo;
			//find current sum
			la = tim;
			ans = min(sum, ans);
			//compare with answer
			slo += val;
			//change slope
		}
		cout<<ans<<endl;
	}
	return 0;
}