public static void main ( String [ ] args ) {
  Scanner in = new Scanner ( System . in ) ;
  int n = in . nextInt ( ) , i , d = 0 , c = 0 ;
  boolean b = false ;
  for ( i = 0 ;
  i < n ;
  i ++ ) {
    int x = in . nextInt ( ) ;
    if ( x == 1 ) {
      b = true ;
      c += d == 0 ? 1 : 2 ;
      d = 0 ;
    }
    else if ( b ) {
      d ++ ;
    }
  }
  in . close ( ) ;
  System . out . println ( c ) ;
}

public static void main ( String [ ] args ) { Scanner in = new Scanner ( System . in ) ; int n = in . nextInt ( ) , i , d = 0 , c = 0 ; boolean b = false ; for ( i = 0 ; i < n ; i ++ ) { int x = in . nextInt ( ) ; if ( x == 1 ) { b = true ; c += d == 0 ? 1 : 2 ; d = 0 ; } else if ( b ) { d ++ ; } } in . close ( ) ; System . out . println ( c ) ; }
(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: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) declarator: (variable_declarator name: (identifier)) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal)) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (local_variable_declaration type: (boolean_type) declarator: (variable_declarator name: (identifier) value: (false))) (for_statement init: (assignment_expression left: (identifier) right: (decimal_integer_literal)) condition: (binary_expression left: (identifier) right: (identifier)) 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)))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (true))) (expression_statement (assignment_expression left: (identifier) right: (ternary_expression condition: (binary_expression left: (identifier) right: (decimal_integer_literal)) consequence: (decimal_integer_literal) alternative: (decimal_integer_literal)))) (expression_statement (assignment_expression left: (identifier) right: (decimal_integer_literal)))) alternative: (if_statement condition: (parenthesized_expression (identifier)) consequence: (block (expression_statement (update_expression (identifier)))))))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))