#include <iostream>
#include <bitset>

using namespace std;

int main()
{
        bitset<32> bitvec;

        int a = 0, b = 1;
        int c = a + b;

        while (c <= 21)
        {
                bitvec.set(c);
                a = b;
                b = c;
                c = a + b;
        }

        cout << "bitvec: " << bitvec << endl;

        return 0;
}