#include<iostream>
using namespace std;
void conti(int &sum,int winnum,int result,int dep){//1赢0输 
	if(dep>21)return;
	if(result==1)winnum++;
	if(result==0)winnum=0;
	if(winnum<10)sum++;
	conti(sum,winnum,1,dep+1); 
	conti(sum,winnum,0,dep+1);
}
int main(){
    int win=0;int sum1=0;int sum2=0;
    conti(sum1,0,1,0);
    conti(sum2,0,0,0); 
    printf("%d",sum1+sum2);
}