//http://www.infoarena.ro/problema/pascal
#include<cstring>
#include<cstdlib>
#include<cstdio>

using namespace std;

int factorial(int x)
{if(x==0) return 1;
    else return x*factorial(x-1);
}
int main()
{int a[20],r,d,i;
FILE *g;
g=fopen("pascal.in","r");
fscanf(g,"%d%d",&r,&d);
fclose(g);
int k;
k=0;
for(i=0;i<=r;i++)
{a[i]=(factorial(r))/(factorial(r-i)*factorial(i));
if(a[i]%2==0)k++;
}
FILE *f;
f=fopen("pascal.out","w");
fprintf(f,"%d",k);
fclose(f);
return 0;
}