public static void main ( String args [ ] ) {
  Scanner scan = new Scanner ( System . in ) ;
  int n = scan . nextInt ( ) ;
  int c = 0 ;
  HashSet < Integer > a = new HashSet < Integer > ( ) ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    int in = scan . nextInt ( ) ;
    a . add ( in ) ;
    if ( in == 0 ) {
      ++ c ;
    }
  }
  int res = a . size ( ) ;
  if ( c != 0 ) {
    -- res ;
  }
  System . out . println ( res ) ;
}

public static void main ( String args [ ] ) { Scanner scan = new Scanner ( System . in ) ; int n = scan . nextInt ( ) ; int c = 0 ; HashSet < Integer > a = new HashSet < Integer > ( ) ; for ( int i = 0 ; i < n ; i ++ ) { int in = scan . nextInt ( ) ; a . add ( in ) ; if ( in == 0 ) { ++ c ; } } int res = a . size ( ) ; if ( c != 0 ) { -- 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))) 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: (decimal_integer_literal))) (local_variable_declaration type: (generic_type (type_identifier) (type_arguments (type_identifier))) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (generic_type (type_identifier) (type_arguments (type_identifier))) arguments: (argument_list)))) (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 (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (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: (identifier) right: (decimal_integer_literal))) consequence: (block (expression_statement (update_expression (identifier))))))) (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 (update_expression (identifier))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))