delNumForBased

#include <iostream>

int main()
{
    int num{ 0 };
    int delNum{ 0 };
    int pos{ 1 };

    std::cout << "Enter number: ";
    std::cin >> num;

    pos = num > 0 ? 1 : -1;
    num *= pos;

    for (int digit{ 0 }, mult{ 1 }; digit = num % 10, num; num /= 10)
    {
        if (digit != 3 and digit != 6)
        {
            delNum += digit * mult;
            mult *= 10;
        }
    }

    std::cout << "Corrected (maybe) number: " << delNum * pos << "\n";
}