public static void main ( String [ ] args ) {
  Scanner in = new Scanner ( System . in ) ;
  String s = in . next ( ) ;
  for ( int i = 0 ;
  i < s . length ( ) ;
  i ++ ) cnt [ s . charAt ( i ) - 'a' ] ++ ;
  int flag = 0 , flag2 = 0 ;
  for ( int i = 0 ;
  i < 26 ;
  i ++ ) {
    if ( cnt [ i ] > 1 ) flag ++ ;
    if ( cnt [ i ] >= 1 ) flag2 ++ ;
  }
  if ( flag2 > 4 ) System . out . println ( "No" ) ;
  else if ( flag >= 2 || flag2 > 3 || ( flag == 1 && flag2 >= 3 ) ) System . out . println ( "Yes" ) ;
  else System . out . println ( "No" ) ;
}

public static void main ( String [ ] args ) { Scanner in = new Scanner ( System . in ) ; String s = in . next ( ) ; for ( int i = 0 ; i < s . length ( ) ; i ++ ) cnt [ s . charAt ( i ) - ' a ' ] ++ ; int flag = 0 , flag2 = 0 ; for ( int i = 0 ; i < 26 ; i ++ ) { if ( cnt [ i ] > 1 ) flag ++ ; if ( cnt [ i ] >= 1 ) flag2 ++ ; } if ( flag2 > 4 ) System . out . println ( " No " ) ; else if ( flag >= 2 || flag2 > 3 || ( flag == 1 && flag2 >= 3 ) ) System . out . println ( " Yes " ) ; else System . out . println ( " No " ) ; }
(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) 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: (expression_statement (update_expression (array_access array: (identifier) index: (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))) right: (character_literal)))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal)) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (decimal_integer_literal)) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal))) consequence: (expression_statement (update_expression (identifier)))) (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal))) consequence: (expression_statement (update_expression (identifier)))))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) consequence: (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (string_literal)))) alternative: (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (binary_expression left: (identifier) right: (decimal_integer_literal)) right: (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (decimal_integer_literal)) right: (binary_expression left: (identifier) right: (decimal_integer_literal)))))) consequence: (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (string_literal)))) alternative: (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (string_literal))))))))