public static void main ( String [ ] args ) {
  FastReader sc = new FastReader ( ) ;
  int n = sc . nextInt ( ) ;
  int a [ ] = new int [ n ] ;
  int c = 0 ;
  double sum = 0 ;
  int b [ ] = new int [ n ] ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    a [ i ] = sc . nextInt ( ) ;
    sum = sum + a [ i ] ;
  }
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    if ( a [ i ] == ( sum - a [ i ] ) / ( n - 1 ) ) {
      b [ c ] = i ;
      c ++ ;
    }
  }
  System . out . println ( c ) ;
  for ( int i = 0 ;
  i < c ;
  i ++ ) {
    System . out . print ( b [ i ] + 1 + " " ) ;
  }
}

public static void main ( String [ ] args ) { FastReader sc = new FastReader ( ) ; int n = sc . nextInt ( ) ; int a [ ] = new int [ n ] ; int c = 0 ; double sum = 0 ; int b [ ] = new int [ n ] ; for ( int i = 0 ; i < n ; i ++ ) { a [ i ] = sc . nextInt ( ) ; sum = sum + a [ i ] ; } for ( int i = 0 ; i < n ; i ++ ) { if ( a [ i ] == ( sum - a [ i ] ) / ( n - 1 ) ) { b [ c ] = i ; c ++ ; } } System . out . println ( c ) ; for ( int i = 0 ; i < c ; i ++ ) { System . out . print ( b [ i ] + 1 + " ▁ " ) ; } }
(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)))) (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) dimensions: (dimensions) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (identifier))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (local_variable_declaration type: (floating_point_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (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: (identifier)) update: (update_expression (identifier)) body: (block (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (identifier) right: (array_access array: (identifier) index: (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: (identifier)) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (binary_expression left: (parenthesized_expression (binary_expression left: (identifier) right: (array_access array: (identifier) index: (identifier)))) right: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal)))))) consequence: (block (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (identifier))) (expression_statement (update_expression (identifier))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (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: (identifier)) update: (update_expression (identifier)) body: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (binary_expression left: (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal)) right: (string_literal)))))))))