Help me in solving BOX95 problem

bug reports
,
1

My issue

When I reverse sort it (like in the code below), and traverse from the start, it gives WA, yet if I sort it in ascending and traverse from back, it passes the test cases. Why is it so, is it some bug?

My code

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

#define ll long long
#define pb push_back
#define sorti(a) sort(a.begin(), a.end())
#define sortr(a) sort(a.begin(), a.end(), greater<int>())
#define print(v) for(auto &i:v) cout<<i<<" "; cout<<endl;
#define forn(i, n) for (int i = 0; i < int(n); i++)

//***************************************************************************************
 
int main()
{
    ios_base::sync_with_stdio(false); cin.tie(NULL);
    int t; cin>>t;
    while(t--)
    {
        ll n; cin>>n;
        vector<ll> a(n);
        forn(i, n)
            cin>>a[i];
        
        sortr(a);
        
        // print(a);

        ll ans=1, X=a[0];
        for(int i=1; i<n; i++)
        {
            if(a[i]<=X)
            {
                X=X^a[i];
            }
            else
            {
                ans++;
                X=a[0];
            } 
        }

        cout<<ans<<endl;
    }

    return 0;
}

Problem Link: BOX95 Problem - CodeChef