#include <bits/stdc++.h>
#define FOR(i,a,b) for(int i = (a); i < (b); ++i)
#define REP(i,n) FOR(i,0,n)
#define SZ(n) (int)(n).size()
using namespace std;
typedef long long ll;
typedef vector<int> VI;

int main() {
	int a[] = { 31,28,31,30,31,30,31,31,30,31,30,31 };
	int ans = 0;
	REP(i, 12) {
		REP(j, a[i]) if (i + 1 == j / 10 + j % 10) ans++;
	}
	cout << ans << endl;
	return 0;
}