func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long MAXN = 300050;   const long long LINF = 0x3f3f3f3f3f3f3f3f;   map<int, int> odd, even;   int buf[MAXN], pre[MAXN];   int main() {     ios::sync_with_stdio(false);     long long n;     cin >> n;     for (long long i = 1; i <= n; i++) {       cin >> buf[i];       pre[i] = pre[i - 1] ^ buf[i];     }     long long res = 0;     even[0]++;     for (int i = 1; i <= n; i++) {       if (i % 2 == 1) {         res += odd[pre[i]];         odd[pre[i]]++;       } else {         res += even[pre[i]];         even[pre[i]]++;       }     }     cout << res << endl;   }   