import java.util.Scanner ;
import java.util.Stack ;
public class Main {
public static void main
( String [ ] args
) { Scanner scanner
= new Scanner
( System .
in ) ; int t = scanner.nextInt ( ) ;
while ( t> 0 ) {
int n = scanner.nextInt ( ) ;
int temp_int;
int [ ] arr = new int [ n+ 1 ] ;
arr[ 0 ] = 0 ;
Vertex vertex = new Vertex( ) ;
for ( int i = 1 ; i <= n; i++ ) {
stack.clear ( ) ;
arr[ i] = scanner.nextInt ( ) ;
arr[ i] = arr[ i- 1 ] ^ arr[ i] ;
temp_int = arr[ i] ;
while ( temp_int > 0 ) {
stack.push ( temp_int% 2) ;
temp_int /= 2 ;
}
while ( stack.size ( ) < 32 )
stack.push ( 0 ) ;
addNum( vertex, stack, i) ;
}
long res = 0 ;
int idx;
for ( int i = 1 ; i <= n; i++ ) {
temp_int = arr[ i] ;
while ( temp_int > 0 ) {
stack.push ( temp_int% 2) ;
temp_int /= 2 ;
}
while ( stack.size ( ) < 32 )
stack.push ( 0 ) ;
idx = maxXor( vertex, stack) ;
if ( ( arr[ i] ^ arr[ idx] ) > res)
res = ( arr[ i] ^ arr[ idx] ) ;
}
t--;
}
}
public static void addNum
( Vertex vertex,
Stack stack,
int idx
) { if ( stack.isEmpty ( ) ) {
vertex.idx = idx;
} else {
int next_bit = ( int ) stack.pop ( ) ;
if ( vertex.vertexes [ next_bit] == null )
vertex.vertexes [ next_bit] = new Vertex( ) ;
addNum( vertex.vertexes [ next_bit] , stack, idx) ;
}
}
public static int maxXor
( Vertex vertex,
Stack stack
) { if ( stack.isEmpty ( ) )
return vertex.idx ;
int num = ( int ) stack.pop ( ) ;
if ( num == 0 ) {
if ( vertex.vertexes [ 1 ] != null )
return maxXor( vertex.vertexes [ 1 ] , stack) ;
else if ( vertex.vertexes [ 0 ] != null )
return maxXor( vertex.vertexes [ 0 ] , stack) ;
else
return 0 ;
} else {
if ( vertex.vertexes [ 0 ] != null )
return maxXor( vertex.vertexes [ 0 ] , stack) ;
else
return 0 ;
}
}
}
class Vertex {
int idx;
Vertex[ ] vertexes = new Vertex[ 2 ] ;
Vertex( ) {
idx = - 1 ;
vertexes[ 0 ] = null ;
vertexes[ 1 ] = null ;
}
}
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