#include <fstream>

using namespace std;
long long k,x,y,L,sol;
ifstream fin ("fractal.in");
ofstream fout ("fractal.out");

int main (){
    // 1 4
    // 2 3
    fin>>k>>x>>y;
    L = (1<<k);
    swap (x,y);
    while (L!=1){
        L/=2;
        if (x <= L){
            if (y > L){
                sol += 3*L*L; // merge 3 cadrane pana acolo (e in 4)
                x = 2*L-y+1;
                y = L-x+1;
                continue;
            }

            swap (x,y);
            continue;

        }

        if (y <= L){
            sol += L*L; // un cadran
            x -= L;
            continue;
        }

        sol += L*L*2; // doua cadrane
        x -= L;
        y -= L;
    }
    fout<<sol;


    return 0;
}