#include <bits/stdc++.h>
using namespace std;
int main() {
  string s, t;
  cin >> s >> t;
  if (s == "monday" && (t == "thursday" || t == "wednesday" || t == "monday"))
    cout << "YES";
  else if (s == "tuesday" &&
           (t == "friday" || t == "thursday" || t == "tuesday"))
    cout << "YES";
  else if (s == "wednesday" &&
           (t == "friday" || t == "saturday" || t == "wednesday"))
    cout << "YES";
  else if (s == "thursday" &&
           (t == "saturday" || t == "sunday" || t == "thursday"))
    cout << "YES";
  else if (s == "friday" && (t == "sunday" || t == "monday" || t == "friday"))
    cout << "YES";
  else if (s == "saturday" &&
           (t == "monday" || t == "tuesday" || t == "saturday"))
    cout << "YES";
  else if (s == "sunday" &&
           (t == "tuesday" || t == "wednesday" || t == "sunday"))
    cout << "YES";
  else
    cout << "NO";
  return 0;
}
