#include <iostream>
#include <algorithm>
#include <vector>

#define INT_MAX 2147483647
#define rep(i, n) for(int i = 0; i < (int)(n); i++)

int func(int n);
using namespace std;
int main() {
	int sum;
	int count = 0;

	for (int i = 1; i < 13; i++) {
		for (int j = 1; j < 32; j++) {

			if (j > 9) sum = func(j);
			else sum = j;

			if (sum == i) count++;
		}
	}
	cout << count << endl;
}

int func(int n) {
	int sum=0;
	if (n < 10) {
		return n;
	} else {
		while (n >= 10) {
			sum += n % 10;
			n /= 10;
		}
		return sum;
	}
}