package main

import (
	"bufio"
	"os"
	"strconv"
	"math/rand"
	"fmt"
	"strings"
)

func main() {
	var days = []int{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}

	var count = 0
	for i := 1; i < 13; i++ {
		for j := 1; j <= days[i-1]; j++ {
			k := j/10+j%10
			if i == k {
				count++
			}
		}
	}
	PrintI(count)
}
func mapToInt(arr []string) []int {
	ret := make([]int, len(arr))
	for i := 0; i < len(arr); i++ {
		var err error
		ret[i], err = strconv.Atoi(arr[i])
		if err != nil {
			panic(err)
		}
	}
	return ret
}

var s = bufio.NewScanner(os.Stdin)

func next() string {

	s.Split(bufio.ScanWords)
	s.Scan()
	return s.Text()
}
func nextLine() string {
	s.Split(bufio.ScanLines)
	s.Scan()
	if nil != s.Err() {
		panic(s.Err())
	}
	return s.Text()
}

func nextInt() int {
	i, e := strconv.Atoi(next())
	if e != nil {
		panic(e)
	}
	return i
}
func nextLong() int64 {
	i, e := strconv.ParseInt(next(), 10, 64)
	if e != nil {
		panic(e)
	}
	return i
}


func randInt(a int , b int) int {
	return rand.Intn(b - a + 1) + a
}

func mapToString(arr []int) []string {
	ret := make([]string, len(arr))
	for i := 0; i < len(arr); i++ {
		ret[i] = strconv.Itoa(arr[i])
	}
	return ret
}


func PrintI(args ...int) {
	fmt.Println(strings.Join(mapToString(args), " "))
}

//aのb乗をします O(log b)
func pow(a int, b int) int {
	total := 1
	tmp := a
	for b > 0 {
		if b%2 == 1 {
			total*=tmp
		}
		b/=2
		tmp*=tmp
	}
	return total
}

func gcd(a, b int64) int64 {
	for {
		c := a % b
		if c == 0 {
			return b
		}
		b = c
		a = b
	}
}
func lcm(a, b int64) int64 {
	return a / gcd(a, b) * b
}