#include <bits/stdc++.h>   using namespace std;   int main() {     int n;     cin >> n;     int a[n];     for (int i = 0; i < n; i++) cin >> a[i];     int d[n];     d[0] = a[0];     map<int, int> even, odd;     even[d[0]]++;     odd[0]++;     long long int c = 0;     for (int i = 1; i < n; i++) {       d[i] = a[i] ^ d[i - 1];       if (i % 2 == 0) {         even[d[i]]++;         if (even.find(d[i]) != even.end()) c += even[d[i]] - 1;       } else {         odd[d[i]]++;         if (odd.find(d[i]) != odd.end()) c += odd[d[i]] - 1;       }     }     cout << c;   }   