public static void main ( String [ ] args ) throws IOException {
  FastScanner input = new FastScanner ( ) ;
  String s = input . next ( ) ;
  int len = s . length ( ) ;
  StringBuilder ans = new StringBuilder ( ) ;
  for ( int i = 0 ;
  i < len ;
  i ++ ) {
    if ( ans . length ( ) > 0 && ans . charAt ( ans . length ( ) - 1 ) == s . charAt ( i ) ) {
      ans . deleteCharAt ( ans . length ( ) - 1 ) ;
    }
    else {
      ans . append ( s . charAt ( i ) ) ;
    }
  }
  System . out . println ( ans ) ;
}

public static void main ( String [ ] args ) throws IOException { FastScanner input = new FastScanner ( ) ; String s = input . next ( ) ; int len = s . length ( ) ; StringBuilder ans = new StringBuilder ( ) ; for ( int i = 0 ; i < len ; i ++ ) { if ( ans . length ( ) > 0 && ans . charAt ( ans . length ( ) - 1 ) == s . charAt ( i ) ) { ans . deleteCharAt ( ans . length ( ) - 1 ) ; } else { ans . append ( s . charAt ( i ) ) ; } } System . out . println ( ans ) ; }
(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)))) (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: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (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 (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) right: (decimal_integer_literal)) right: (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) right: (decimal_integer_literal)))) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))))) consequence: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) right: (decimal_integer_literal)))))) alternative: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))