import std.algorithm, std.array, std.container, std.range, std.bitmanip;
import std.numeric, std.math, std.bigint, std.random;
import std.string, std.conv, std.stdio, std.typecons;

const auto days = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];

void main()
{
  auto r = 0;
  foreach (m; 1..12 + 1) {
    foreach (d; 1..days[m - 1] + 1) {
      auto e = d / 10 + d % 10;
      if (m == e) r += 1;
    }
  }
  writeln(r);
}