public static void main ( String [ ] args ) {
  FastScanner scan = new FastScanner ( ) ;
  int t = scan . nextInt ( ) ;
  int a [ ] = new int [ t ] ;
  for ( int i = 0 ;
  i < t ;
  ++ i ) {
    a [ i ] = scan . nextInt ( ) ;
  }
  Arrays . sort ( a ) ;
  if ( a [ 0 ] == 1 ) {
    System . out . print ( "-1" ) ;
  }
  else {
    System . out . print ( 1 ) ;
  }
}

public static void main ( String [ ] args ) { FastScanner scan = new FastScanner ( ) ; int t = scan . nextInt ( ) ; int a [ ] = new int [ t ] ; for ( int i = 0 ; i < t ; ++ i ) { a [ i ] = scan . nextInt ( ) ; } Arrays . sort ( a ) ; if ( a [ 0 ] == 1 ) { System . out . print ( " - 1" ) ; } else { System . out . print ( 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)))) (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) dimensions: (dimensions) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (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: (block (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))) (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (decimal_integer_literal)) right: (decimal_integer_literal))) consequence: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (string_literal))))) alternative: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (decimal_integer_literal))))))))