#include <bits/stdc++.h>
using namespace std;
#define ll long long

ll n,c;
ll a[1100000];
ll cnt[1100000];
ll sum[1100000];
ll hf,ans,now;

ll C(ll x){
	if (x<=1) return 0;
    return x*(x-1)/2;
}

int main(){
    freopen("Triplets.in","r",stdin);
    freopen("Triplets.out","w",stdout);
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    cin>>n>>c;
    for (int i=1;i<=n;i++){
        cin>>a[i];
        cnt[a[i]]++;
    }
    hf=c/2;
    for (int i=1;i<=hf;i++) now+=cnt[i];
    for (int i=0;i<c;i++){
        ans+=cnt[i]*C(now);
    	if (c%2==0) ans+=C(cnt[i])*(now-cnt[(i+hf)%c]);
    	else ans+=C(cnt[i])*now;
        now-=cnt[(i+1)%c];
        now+=cnt[(i+hf+1)%c];
        if (cnt[i]>=3) ans+=cnt[i]*(cnt[i]-1)*(cnt[i]-2)/6;
    }
    ll sum=n*(n-1)*(n-2)/6;
    cout<<sum-ans<<'\n';
    return 0;
}