public static void main ( String [ ] args ) {
  Scanner input = new Scanner ( System . in ) ;
  int totalCases = input . nextInt ( ) ;
  for ( int caseNumber = 1 ;
  caseNumber <= totalCases ;
  caseNumber ++ ) {
    int arrayLength = input . nextInt ( ) ;
    int previousElement = Integer . MIN_VALUE ;
    int maximumDifference = 0 ;
    for ( int index = 0 ;
    index < arrayLength ;
    index ++ ) {
      int currentElement = input . nextInt ( ) ;
      if ( previousElement > currentElement ) {
        maximumDifference = Math . max ( maximumDifference , previousElement - currentElement ) ;
      }
      else {
        previousElement = currentElement ;
      }
    }
    System . out . println ( ( int ) Math . ceil ( Math . log ( maximumDifference + 1 ) / Math . log ( 2 ) ) ) ;
  }
}

public static void main ( String [ ] args ) { Scanner input = new Scanner ( System . in ) ; int totalCases = input . nextInt ( ) ; for ( int caseNumber = 1 ; caseNumber <= totalCases ; caseNumber ++ ) { int arrayLength = input . nextInt ( ) ; int previousElement = Integer . MIN_VALUE ; int maximumDifference = 0 ; for ( int index = 0 ; index < arrayLength ; index ++ ) { int currentElement = input . nextInt ( ) ; if ( previousElement > currentElement ) { maximumDifference = Math . max ( maximumDifference , previousElement - currentElement ) ; } else { previousElement = currentElement ; } } System . out . println ( ( int ) Math . ceil ( Math . log ( maximumDifference + 1 ) / Math . log ( 2 ) ) ) ; } }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (array_type element: (type_identifier) dimensions: (dimensions)) name: (identifier))) body: (block (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_identifier) arguments: (argument_list (field_access object: (identifier) field: (identifier)))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (field_access object: (identifier) field: (identifier)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier) (binary_expression left: (identifier) right: (identifier))))))) alternative: (block (expression_statement (assignment_expression left: (identifier) right: (identifier))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (cast_expression type: (integral_type) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (identifier) right: (decimal_integer_literal)))) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (decimal_integer_literal))))))))))))))