public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  int n = sc . nextInt ( ) ;
  int [ ] ar = new int [ n ] ;
  int lastin = 0 ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    ar [ i ] = sc . nextInt ( ) ;
    if ( ar [ i ] == 1 ) {
      lastin = i ;
    }
  }
  long c = 0 ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    if ( i < n - 1 ) {
      if ( ar [ i ] == 1 ) {
        c ++ ;
        if ( ar [ i + 1 ] != 1 && ( i + 1 ) <= lastin ) {
          c ++ ;
        }
      }
    }
    else {
      if ( ar [ i ] == 1 ) {
        c ++ ;
      }
    }
  }
  System . out . println ( c ) ;
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; int n = sc . nextInt ( ) ; int [ ] ar = new int [ n ] ; int lastin = 0 ; for ( int i = 0 ; i < n ; i ++ ) { ar [ i ] = sc . nextInt ( ) ; if ( ar [ i ] == 1 ) { lastin = i ; } } long c = 0 ; for ( int i = 0 ; i < n ; i ++ ) { if ( i < n - 1 ) { if ( ar [ i ] == 1 ) { c ++ ; if ( ar [ i + 1 ] != 1 && ( i + 1 ) <= lastin ) { c ++ ; } } } else { if ( ar [ i ] == 1 ) { c ++ ; } } } 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)))) (local_variable_declaration type: (array_type element: (integral_type) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) 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))) (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)))) (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (identifier))))))) (local_variable_declaration type: (integral_type) 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: (identifier)) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal)))) consequence: (block (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal))) consequence: (block (expression_statement (update_expression (identifier))) (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (decimal_integer_literal)) right: (binary_expression left: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (identifier)))) consequence: (block (expression_statement (update_expression (identifier)))))))) alternative: (block (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal))) consequence: (block (expression_statement (update_expression (identifier))))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))