#include <bits/stdc++.h>
using namespace std;
namespace IO {
const int MAXIOSIZE = 1 << 24 | 1;
unsigned char buf[MAXIOSIZE], *p1, *p2;
template <typename T>
void read(T& x) {
  x = 0;
  char ch =
      (p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, 1 << 24, stdin), p1 == p2)
           ? EOF
           : *p1++);
  bool flg = false;
  for (; ch < '0' || '9' < ch;
       ch = (p1 == p2 &&
                     (p2 = (p1 = buf) + fread(buf, 1, 1 << 24, stdin), p1 == p2)
                 ? EOF
                 : *p1++))
    if (ch == '-') flg |= true;
  for (; '0' <= ch && ch <= '9';
       ch = (p1 == p2 &&
                     (p2 = (p1 = buf) + fread(buf, 1, 1 << 24, stdin), p1 == p2)
                 ? EOF
                 : *p1++))
    x = x * 10 + ch - '0';
  flg ? x = -x : 0;
}
template <typename T>
void out(const T& x) {
  if (x > 9) out(x / 10);
  putchar(x % 10 + '0');
}
template <typename T>
inline void write(const T& x, const char& ed = ' ') {
  if (x < 0)
    putchar('-'), out(-x);
  else
    out(x);
  putchar(ed);
}
}  // namespace IO
const string date[] = {"monday", "tuesday",  "wednesday", "thursday",
                       "friday", "saturday", "sunday"};
string s, t;
int main() {
  cin >> s >> t;
  int t1, t2;
  for (int i = (0), iend = (7); i < iend; ++i) {
    if (s == date[i]) t1 = i;
    if (t == date[i]) t2 = i;
  }
  int d = (t2 - t1 + 7) % 7;
  if (d == 3 || d == 0 || d == 2) return 0 * puts("YES");
  puts("NO");
  return 0;
}
