#include <bits/stdc++.h>
using namespace std;

int main() {
	int m = 1, d = 1, ans = 0;
	
	while(true) {
		if(d / 10 + d % 10 == m) ans ++;
		
		d ++;
		if(m == 2) {
			if(d >= 29) d = 0, m ++;
		} else if(m == 4 || m == 6 || m == 9 || m == 11) {
			if(d >= 31) d = 0, m ++;
		} else {
			if(d >= 32) d = 0, m ++;
		}
		if(m >= 13) break;
	}
	
	cout << ans << endl;
	
	return 0;
}