public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  int n = sc . nextInt ( ) ;
  int d = sc . nextInt ( ) ;
  int [ ] arr = new int [ n ] ;
  int sum = 0 ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    arr [ i ] = sc . nextInt ( ) ;
    sum += arr [ i ] ;
  }
  sc . close ( ) ;
  if ( ( sum + ( n - 1 ) * 10 ) <= d ) {
    int ans = ( n - 1 ) * 2 ;
    ans = ans + ( d - ( sum + ( n - 1 ) * 10 ) ) / 5 ;
    System . out . println ( ans ) ;
  }
  else System . out . println ( - 1 ) ;
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; int n = sc . nextInt ( ) ; int d = sc . nextInt ( ) ; int [ ] arr = new int [ n ] ; int sum = 0 ; for ( int i = 0 ; i < n ; i ++ ) { arr [ i ] = sc . nextInt ( ) ; sum += arr [ i ] ; } sc . close ( ) ; if ( ( sum + ( n - 1 ) * 10 ) <= d ) { int ans = ( n - 1 ) * 2 ; ans = ans + ( d - ( sum + ( n - 1 ) * 10 ) ) / 5 ; System . out . println ( ans ) ; } else System . out . println ( - 1 ) ; }
(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: (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)))) (expression_statement (assignment_expression left: (identifier) right: (array_access array: (identifier) index: (identifier)))))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) (if_statement condition: (parenthesized_expression (binary_expression left: (parenthesized_expression (binary_expression left: (identifier) right: (binary_expression left: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (decimal_integer_literal)))) right: (identifier))) consequence: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (decimal_integer_literal)))) (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (identifier) right: (binary_expression left: (parenthesized_expression (binary_expression left: (identifier) right: (parenthesized_expression (binary_expression left: (identifier) right: (binary_expression left: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (decimal_integer_literal)))))) right: (decimal_integer_literal))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))) alternative: (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (unary_expression operand: (decimal_integer_literal))))))))