package main

import (
	"fmt"
)

func main() {
	ms := []int{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
	ans := 0
	for i := 1; i <= 31; i++ {
		m := (i / 10) + (i % 10)
		if i <= ms[m] {
			ans++
			// fmt.Printf("%d / %d\n", m, i)
		}
	}

	fmt.Println(ans)
}