public static void main ( String [ ] args ) {
  Scanner scanner = new Scanner ( System . in ) ;
  String s ;
  int x = 0 , n , flag ;
  n = scanner . nextInt ( ) ;
  s = scanner . next ( ) ;
  while ( s . contains ( "xxx" ) ) {
    s = s . replaceFirst ( "xxx" , "xx" ) ;
    x ++ ;
  }
  System . out . println ( x ) ;
}

public static void main ( String [ ] args ) { Scanner scanner = new Scanner ( System . in ) ; String s ; int x = 0 , n , flag ; n = scanner . nextInt ( ) ; s = scanner . next ( ) ; while ( s . contains ( " xxx " ) ) { s = s . replaceFirst ( " xxx " , " xx " ) ; x ++ ; } System . out . println ( x ) ; }
(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: (type_identifier) declarator: (variable_declarator name: (identifier))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal)) declarator: (variable_declarator name: (identifier)) declarator: (variable_declarator name: (identifier))) (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (while_statement condition: (parenthesized_expression (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (string_literal)))) body: (block (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (string_literal) (string_literal))))) (expression_statement (update_expression (identifier))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))