NSSortDescriptor ordenar con número un string

NSArray *sortedArray;
sortedArray = [listado sortedArrayUsingComparator:(NSComparator)^(id a, id b) {
Modelo *modelo1 = a;
Modelo *modelo2 = b;
NSNumber *num1 = [NSNumber numberWithInt:[modelo1.stringAComparar intValue]];
NSNumber *num2 = [NSNumber numberWithInt:[modelo2.stringAComparar intValue]];

return [num2 compare:num1];
}];
listado = [sortedArray mutableCopy];

UIAlertController: style action sheet

UIAlertController *alertController = [UIAlertController
											  alertControllerWithTitle:nil
											  message:nil
											  preferredStyle:UIAlertControllerStyleActionSheet];
		
		UIAlertAction *cancelar = [UIAlertAction
									   actionWithTitle:NSLocalizedString(@"Cancelar", nil)
									   style:UIAlertActionStyleCancel
									   handler:^(UIAlertAction *action)
									   {
										   NSLog(@"Cancel action");
									   }];
		
		UIAlertAction *accion = [UIAlertAction
								 actionWithTitle:NSLocalizedString(@"Acción", nil)
								 style:UIAlertActionStyleDefault
								 handler:^(UIAlertAction *action)
								 {
									
								 }];
		
		NSMutableAttributedString *textoTitulo = [[NSMutableAttributedString alloc] initWithString:NSLocalizedString(@"Título...", nil)];
		[textoTitulo addAttribute:NSFontAttributeName
					  value:[UIFont fontWithName:NSLocalizedString(@"tipoLetra", nil) size:19.0]
					  range:NSMakeRange(0, textoTitulo.length)];
		[alertController setValue:textoTitulo forKey:@"attributedTitle"];
		
		[alertController addAction:cancelar];
		[alertController accion];
		
		[self presentViewController:alertController animated:YES completion:nil];