public static void main ( String hi [ ] ) throws Exception {
  BufferedReader infile = new BufferedReader ( new InputStreamReader ( System . in ) ) ;
  StringTokenizer st = new StringTokenizer ( infile . readLine ( ) ) ;
  int N = Integer . parseInt ( st . nextToken ( ) ) ;
  char [ ] arr = infile . readLine ( ) . toCharArray ( ) ;
  int res = N ;
  for ( int i = 1 ;
  i < N ;
  i ++ ) if ( arr [ i ] != arr [ i - 1 ] ) {
    i ++ ;
    res -- ;
  }
  System . out . println ( res ) ;
}

public static void main ( String hi [ ] ) throws Exception { BufferedReader infile = new BufferedReader ( new InputStreamReader ( System . in ) ) ; StringTokenizer st = new StringTokenizer ( infile . readLine ( ) ) ; int N = Integer . parseInt ( st . nextToken ( ) ) ; char [ ] arr = infile . readLine ( ) . toCharArray ( ) ; int res = N ; for ( int i = 1 ; i < N ; i ++ ) if ( arr [ i ] != arr [ i - 1 ] ) { i ++ ; res -- ; } System . out . println ( res ) ; }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (type_identifier) name: (identifier) dimensions: (dimensions))) (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 (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: (object_creation_expression type: (type_identifier) arguments: (argument_list (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 (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))))) (local_variable_declaration type: (array_type element: (integral_type) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (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: (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))))) consequence: (block (expression_statement (update_expression (identifier))) (expression_statement (update_expression (identifier)))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))