sa

const int MAXN  = 3e5 + 50 ;
int  A[ MAXN ] ;
int  S[ MAXN ] ;
int  T[ 4*MAXN ] ;
int N ;
int LB = -1 ;
int UB = INT_MAX;

int  Case1( int idx )
 {
         int Limit = ( 1 << idx );
         if( S[idx] < Limit  )return 0  ;
         int cnt1 = X.order_of_key( mp( 0 , LB ) ) ; // jo 0  se strictly chote hain
         int cnt2 = X.order_of_key( mp( S[idx] - Limit  , UB ) ) ;
         return cnt2 - cnt1 ;

 }

int Case2 ( int idx )
  {
       int Limit = ( 1 << idx )  ;
       int cnt1 = X.order_of_key( mp( S[idx]+1 , LB ) ) ; // jo 0  se strictly chote hain
       int cnt2 = X.order_of_key( mp( S[idx] + Limit  , UB ) ) ;
       return cnt2 - cnt1 ;
  }

bool check ( int idx  )
 {
    X.clear() ;
    const int M = ( 1 << (idx + 1) )  ;
    S[0] = A[0]%M ;
    for( int  i = 1 ; i < N ; i ++ )
       S[i] = ( S[i-1] + A[i] )%M  ;
    //! Case 1 : S[j] >= 0 and S[i] - 2^b
    //! Case 2 : S[i] + 1 and S[i]  + 2^b

    int sum = 0 ;
    FOR( i ,  N )
      {
         if( (1<<idx) & A[i] )sum ++ ;
         sum += Case1 (  i ) ;
         cout<<sum<<endl;
         sum += Case2 (  i ) ;
         cout<<sum<<endl;
         X.insert(mp(S[i],i)) ;

      }

      cout<<idx<<" "<<sum<<endl;
      return (sum&1);
 }
int main ( )
 {
    scanf("%d",&N) ;
    FOR( i , N )scanf("%d",&A[i] ) ;
    int ans = 0 ;
    for( int i = 0 ; i  < 31 ; i ++ )
       if( check( i ) )ans = ans | ( 1 << i ) ;

     cout<<ans<<endl;
 }