public static void main ( String [ ] args ) {
  FastReader sc = new FastReader ( ) ;
  int n = sc . nextInt ( ) ;
  int a [ ] = sc . nextIntArray ( n ) ;
  HashSet < Integer > hs = new HashSet < > ( ) ;
  for ( int i : a ) {
    hs . add ( 0 - i ) ;
  }
  System . out . println ( hs . contains ( 0 ) ? hs . size ( ) - 1 : hs . size ( ) ) ;
}

public static void main ( String [ ] args ) { FastReader sc = new FastReader ( ) ; int n = sc . nextInt ( ) ; int a [ ] = sc . nextIntArray ( n ) ; HashSet < Integer > hs = new HashSet < > ( ) ; for ( int i : a ) { hs . add ( 0 - i ) ; } System . out . println ( hs . contains ( 0 ) ? hs . size ( ) - 1 : hs . size ( ) ) ; }
(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: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))))) (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)) arguments: (argument_list)))) (enhanced_for_statement type: (integral_type) name: (identifier) value: (identifier) body: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (decimal_integer_literal) right: (identifier))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (ternary_expression condition: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (decimal_integer_literal))) consequence: (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) right: (decimal_integer_literal)) alternative: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))))))))