biggestbignum

class biggestbignum
{
    const static uint32_t M=1000000000;
    uint32_t a,b;
public:
    biggestbignum ( uint32_t a_, uint32_t b_ ): a(a_), b(b_) {};
    biggestbignum ( uint32_t a_): a(a_), b(0) {};

    biggestbignum operator * (const biggestbignum &other) const
    {
        uint64_t A = a *(uint64_t) other.a;
        uint64_t B = (a *(uint64_t) other.b) + (b *(uint64_t) other.a) + A/M;
        return biggestbignum ( A%M, B%M );
    }
    biggestbignum operator + (const biggestbignum &other)
    {
        biggestbignum res( (a+other.a), (b+other.b) );
        res.b+=res.a/M;
        res.b%=M;
        res.a%=M;
        return res;
    }
    friend ostream& operator<<(ostream& os, const biggestbignum& x);
};

ostream& operator<<(ostream& os, const biggestbignum& x)
{
    if (x.b>0)
        os<<x.b<<setw(9)<<std::setfill ('0');
    os<<x.a;//<<" hi "<<x.b<<" lo "<<x.a;
    return os;
}