public static void solve ( ) {
  int n = s . nextInt ( ) ;
  String str = s . next ( ) ;
  char ch [ ] = new char [ n ] ;
  for ( int i = 0 ;
  i < str . length ( ) ;
  i ++ ) ch [ i ] = str . charAt ( i ) ;
  Arrays . sort ( ch ) ;
  for ( int i = 0 ;
  i < str . length ( ) ;
  i ++ ) System . out . print ( ch [ i ] ) ;
}

public static void solve ( ) { int n = s . nextInt ( ) ; String str = s . next ( ) ; char ch [ ] = new char [ n ] ; for ( int i = 0 ; i < str . length ( ) ; i ++ ) ch [ i ] = str . charAt ( i ) ; Arrays . sort ( ch ) ; for ( int i = 0 ; i < str . length ( ) ; i ++ ) System . out . print ( ch [ i ] ) ; }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters) 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: (type_identifier) 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) dimensions: (dimensions) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (identifier))))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) update: (update_expression (identifier)) body: (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) update: (update_expression (identifier)) body: (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (array_access array: (identifier) index: (identifier))))))))