public static void main ( String [ ] args ) throws Exception {
  Scanner scan = new Scanner ( System . in ) ;
  int n = scan . nextInt ( ) ;
  scan . nextLine ( ) ;
  String s = scan . nextLine ( ) ;
  int Xnum = 0 ;
  int xnum = 0 ;
  StringBuilder result = new StringBuilder ( ) ;
  for ( int j = 0 ;
  j < n ;
  j ++ ) {
    char ch = s . charAt ( j ) ;
    if ( ch == 'X' ) {
      Xnum ++ ;
    }
    else {
      xnum ++ ;
    }
  }
  if ( Xnum == xnum ) {
    result . append ( "0\n" + s ) ;
  }
  else {
    int r = Math . max ( Xnum - n / 2 , xnum - n / 2 ) ;
    StringBuilder sr = new StringBuilder ( ) ;
    for ( int j = 0 ;
    j < n ;
    j ++ ) {
      char ch = s . charAt ( j ) ;
      if ( ch == 'X' && Xnum > xnum && r > 0 ) {
        sr . append ( 'x' ) ;
        r -- ;
      }
      else if ( ch == 'x' && Xnum < xnum && r > 0 ) {
        sr . append ( 'X' ) ;
        r -- ;
      }
      else {
        sr . append ( ch ) ;
      }
    }
    result . append ( Math . max ( Xnum - n / 2 , xnum - n / 2 ) + "\n" + sr ) ;
  }
  System . out . println ( result ) ;
}

public static void main ( String [ ] args ) throws Exception { Scanner scan = new Scanner ( System . in ) ; int n = scan . nextInt ( ) ; scan . nextLine ( ) ; String s = scan . nextLine ( ) ; int Xnum = 0 ; int xnum = 0 ; StringBuilder result = new StringBuilder ( ) ; for ( int j = 0 ; j < n ; j ++ ) { char ch = s . charAt ( j ) ; if ( ch == ' X ' ) { Xnum ++ ; } else { xnum ++ ; } } if ( Xnum == xnum ) { result . append ( "0 \n " + s ) ; } else { int r = Math . max ( Xnum - n / 2 , xnum - n / 2 ) ; StringBuilder sr = new StringBuilder ( ) ; for ( int j = 0 ; j < n ; j ++ ) { char ch = s . charAt ( j ) ; if ( ch == ' X ' && Xnum > xnum && r > 0 ) { sr . append ( ' x ' ) ; r -- ; } else if ( ch == ' x ' && Xnum < xnum && r > 0 ) { sr . append ( ' X ' ) ; r -- ; } else { sr . append ( ch ) ; } } result . append ( Math . max ( Xnum - n / 2 , xnum - n / 2 ) + " \n " + sr ) ; } System . out . println ( result ) ; }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (array_type element: (type_identifier) dimensions: (dimensions)) name: (identifier))) (throws (type_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)))) (expression_statement (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) value: (decimal_integer_literal))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_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 (identifier))))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (character_literal))) consequence: (block (expression_statement (update_expression (identifier)))) alternative: (block (expression_statement (update_expression (identifier))))))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) consequence: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (string_literal) right: (identifier)))))) alternative: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal))) (binary_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal))))))) (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_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 (identifier))))) (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (binary_expression left: (identifier) right: (character_literal)) right: (binary_expression left: (identifier) right: (identifier))) right: (binary_expression left: (identifier) right: (decimal_integer_literal)))) consequence: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (character_literal)))) (expression_statement (update_expression (identifier)))) alternative: (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (binary_expression left: (identifier) right: (character_literal)) right: (binary_expression left: (identifier) right: (identifier))) right: (binary_expression left: (identifier) right: (decimal_integer_literal)))) consequence: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (character_literal)))) (expression_statement (update_expression (identifier)))) alternative: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))))))))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal))) (binary_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal))))) right: (string_literal)) right: (identifier))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))