#include<stdio.h>

int main(){
  int i,j;
  int d;
  int count=0;
  int day[13]={31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  for(i=1; i <= 12; i++){
    for(j=1; j <=day[i-1]; j++){
      d = j/10 + j%10;
      if(i == d){
        //printf("%d,%d\n", i, j);
        count++;
      }
    }
  }
  printf("%d\n", count);
  return 0;
}