#include <bits/stdc++.h>
using namespace std;
const int N = 1000110;
string str[7] = {"monday", "tuesday",  "wednesday", "thursday",
                 "friday", "saturday", "sunday"};
int main() {
  string s, s1;
  while (cin >> s >> s1) {
    int i;
    int a, b;
    for (i = 0; i < 7; i++) {
      if (s == str[i]) a = i;
      if (s1 == str[i]) b = i;
    }
    if (b - a == 3 || b - a == 0 || b - a == -4 || b - a == 2 || b - a == -4 ||
        b - a == 2 || b - a == 3 || b - a == -4 || b - a == 2 || b - a == 3 ||
        b - a == -5)
      cout << "YES" << endl;
    else
      cout << "NO" << endl;
  }
  return 0;
}
