#include <bits/stdc++.h>

using namespace std;

ifstream fin("fractal.in");
ofstream fout("fractal.out");

int k, x, y, cost;

void divide(int k, int x, int y, int a, int b, int l)
{
    if(k==0)
        return ;
    if(a+l/2-1>=x && b+l/2-1>=y)
        divide(k-1,x,y,a,b,l/2);
    else if(a+l/2<=x && b+l/2-1>=y)
    {
        cost+=(l/2)*(l/2);
        divide(k-1,x,y,a+l/2,b,l/2);
    }
    else if(a+l/2<=x && b+l/2<=y)
    {
        cost+=2*(l/2)*(l/2);
        divide(k-1,x,y,a+l/2,b+l/2,l/2);
    }
    else
    {
        cost+=3*(l/2)*(l/2);
        divide(k-1,x,y,a,b+l/2,l/2);
    }
}

int main()
{
    fin>>k>>x>>y;
    int i, j, l;
    l=(int)powl(2,k);
    divide(k,x,y,1,1,l);
    fout<<cost<<'\n';
    return 0;
}