#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm> 
#include <map>
#include <vector> 

using namespace std;

int main(){
	
	int d[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};
	int ans=0;
	for(int i=1;i<=12;i++){
		for(int j=1;j<=d[i];j++){
			if(i==j%10+j/10)ans++;
		}
	}
	printf("%d\n",ans);
	
	
	
	
	
	return 0;
}