szybkie potegowanie

#include <iostream>
#include <sstream>

using namespace std;
string x;

int main()
{
    unsigned long long a, b;
    cin>>b;
    cin>>a;

    while (a!=0)
    {
        if (a%2==1)
            x=x+'1';
        else x=x+'0';
        a/=2;
    }

    unsigned long long wynik=1;
    unsigned long long ptg=1;

    for (unsigned long long i=0; i<x.length(); i++)
    {
        unsigned long long pom=1;

        if (x[i]=='1')
        {
            for (unsigned long long j=1; j<=ptg; j++)
                pom*=b;

            wynik*=pom;
        }
        ptg*=2;
    }

    cout<<wynik;

    return 0;
}