switch (option)
		{
		case 13:
		{
				   int identityCard = 0, rightPartOfTheNumber = 0, checkDigit = 0, sum = 0, i = 0, counter = 0;
				   bool doubleOrOddDigit = true, isSumTrue = true;
				   cout << "please enter your id : ";
				   cin  >> identityCard;
				   checkDigit = identityCard % 10;
				   identityCard /= 10;
				   for (i = 0; identityCard > 0; counter++)
				   {
					   rightPartOfTheNumber = identityCard % 10;
					   if (doubleOrOddDigit)
					   {
						   rightPartOfTheNumber *= 2;
						   sum += rightPartOfTheNumber % 10 + rightPartOfTheNumber / 10;
					   }
					   else
						   sum = sum + identityCard % 10;
					   identityCard /= 10;
					   doubleOrOddDigit = !doubleOrOddDigit;

				   }
				   if ((sum + checkDigit) % 10 != 0)
				   {
					   isSumTrue = false;
				   }
				   if (isSumTrue)
					   cout << "you wrote correct id \n";
				   else
					   cout << "you wrote incorrect id \n";
				   break;
		}
		}