#include<iostream>
using namespace std;

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