#include<fstream>
using namespace std;
ifstream f("fractal.in");
ofstream g("fractal.out");
int k,x,y,n,a[20],sol;

void fr(int k,int x,int y)
{
    int p;
    if(k==0)
    return;
    p=1<<(k-1);
    if((x<=p)&&(y<=p))
        fr(k-1,y,x);
    else if(y<=p)
    {
        sol+=a[k-1]+1;
        fr(k-1,x-p,y);
    }
    else if (x<=p)
    {
        sol+=3*a[k-1]+3;
        fr(k-1,2*p-y+1,p-x+1);
    }
    else
    {
        sol+=2*a[k-1]+2;
        fr(k-1,x-p,y-p);
    }

}


int main()
{
    f>>k>>y>>x;
    for(int i=1;i<=k;i++)
    a[i]=4*a[i-1]+3;

    fr(k,x,y);
    g<<sol;

}