public static void main ( String [ ] args ) {
  int total = 0 ;
  Scanner sc = new Scanner ( System . in ) ;
  int N = sc . nextInt ( ) ;
  String C = sc . next ( ) ;
  for ( int i = 0 ;
  i < C . length ( ) ;
  i ++ ) {
    char ca = C . charAt ( i ) ;
    if ( ca == 'A' ) {
      total += 4 ;
    }
    else if ( ca == 'B' ) {
      total += 3 ;
    }
    else if ( ca == 'C' ) {
      total += 2 ;
    }
    else if ( ca == 'D' ) {
      total += 1 ;
    }
  }
  BigDecimal divided = new BigDecimal ( total ) ;
  BigDecimal divisor = new BigDecimal ( N ) ;
  BigDecimal ans = divided . divide ( divisor , 10 , RoundingMode . HALF_UP ) ;
  System . out . println ( ans ) ;
  sc . close ( ) ;
}

public static void main ( String [ ] args ) { int total = 0 ; Scanner sc = new Scanner ( System . in ) ; int N = sc . nextInt ( ) ; String C = sc . next ( ) ; for ( int i = 0 ; i < C . length ( ) ; i ++ ) { char ca = C . charAt ( i ) ; if ( ca == ' A ' ) { total += 4 ; } else if ( ca == ' B ' ) { total += 3 ; } else if ( ca == ' C ' ) { total += 2 ; } else if ( ca == ' D ' ) { total += 1 ; } } BigDecimal divided = new BigDecimal ( total ) ; BigDecimal divisor = new BigDecimal ( N ) ; BigDecimal ans = divided . divide ( divisor , 10 , RoundingMode . HALF_UP ) ; System . out . println ( ans ) ; sc . close ( ) ; }
(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: (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 (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)))) (local_variable_declaration type: (type_identifier) 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: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) 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 (assignment_expression left: (identifier) right: (decimal_integer_literal)))) alternative: (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (character_literal))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (decimal_integer_literal)))) alternative: (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (character_literal))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (decimal_integer_literal)))) alternative: (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (character_literal))) consequence: (block (expression_statement (assignment_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 (identifier))))) (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_identifier) arguments: (argument_list (identifier))))) (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier) (decimal_integer_literal) (field_access object: (identifier) field: (identifier)))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier)))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))))