public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  int A = sc . nextInt ( ) ;
  int B = sc . nextInt ( ) ;
  int K = sc . nextInt ( ) ;
  ArrayList < Integer > list = new ArrayList < Integer > ( ) ;
  int max = Math . max ( A , B ) ;
  for ( int i = 1 ;
  i <= max ;
  i ++ ) {
    if ( A % i == 0 && B % i == 0 ) {
      list . add ( new Integer ( i ) ) ;
    }
  }
  System . out . println ( list . get ( list . size ( ) - K ) ) ;
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; int A = sc . nextInt ( ) ; int B = sc . nextInt ( ) ; int K = sc . nextInt ( ) ; ArrayList < Integer > list = new ArrayList < Integer > ( ) ; int max = Math . max ( A , B ) ; for ( int i = 1 ; i <= max ; i ++ ) { if ( A % i == 0 && B % i == 0 ) { list . add ( new Integer ( i ) ) ; } } System . out . println ( list . get ( list . size ( ) - K ) ) ; }
(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: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (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)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier) (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 (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (decimal_integer_literal)) right: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (decimal_integer_literal)))) consequence: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (object_creation_expression type: (type_identifier) arguments: (argument_list (identifier)))))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) right: (identifier)))))))))