#include <bits/stdc++.h>
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx")
using namespace std;
inline bool isDigit(char c) { return '0' <= c && c <= '9'; }
template <class T>
inline T sqr(T x) {
  return x * x;
}
template <class T>
inline bool isSquare(T x) {
  int y = sqrt(x + 0.5);
  return (y * y) == x;
}
template <class T1, class T2>
inline T1 gcd(T1 a, T2 b) {
  return b ? gcd(b, a % b) : a;
}
template <class T1, class T2>
inline T1 eqMin(T1& x, const T2& y) {
  if (T1(y) < x) return x = y;
  return x;
}
template <class T1, class T2>
inline T1 eqMax(T1& x, const T2& y) {
  if (T1(y) > x) return x = y;
  return x;
}
template <class T1, class T2>
inline T1 min(const T1& x, const T2& y) {
  return x < (T1)y ? x : (T1)y;
}
template <class T1, class T2>
inline T1 max(T1& x, const T2& y) {
  return x > (T1)y ? x : (T1)y;
}
template <typename T>
inline T getint() {
  T x = 0, p = 1;
  char ch;
  do {
    ch = getchar();
  } while (ch <= ' ');
  if (ch == '-') p = -1, ch = getchar();
  while (ch >= '0' && ch <= '9') x = x * 10 + ch - '0', ch = getchar();
  return x * p;
}
template <class T1, class T2>
ostream& operator<<(ostream& os, const pair<T1, T2>& p) {
  return os << '(' << p.first << ", " << p.second << ')';
}
template <class T>
ostream& operator<<(ostream& os, const vector<T>& v) {
  os << '{';
  bool was = false;
  for (const T& x : v) {
    if (was) os << ", ";
    was = true;
    os << x;
  }
  os << '}';
  return os;
}
template <class T>
ostream& operator<<(ostream& os, const set<T>& v) {
  os << '[';
  bool was = false;
  for (const T& x : v) {
    if (was) os << ", ";
    was = true;
    os << x;
  }
  os << ']';
  return os;
}
template <class T>
ostream& operator<<(ostream& os, const multiset<T>& v) {
  os << '[';
  bool was = false;
  for (const T& x : v) {
    if (was) os << ", ";
    was = true;
    os << x;
  }
  os << ']';
  return os;
}
template <class T1, class T2>
ostream& operator<<(ostream& os, const map<T1, T2>& m) {
  os << '<';
  bool was = false;
  for (const auto& x : m) {
    if (was) os << ", ";
    was = true;
    os << x;
  }
  os << '>';
  return os;
}
template <size_t sz>
ostream& operator<<(ostream& os, const bitset<sz>& bit) {
  os << '/';
  for (int i = 0; i < sz; i++) os << bit[i];
  os << '\\';
  return os;
}
const double PI = acos(-1);
const double EPS = 1e-8;
const int INF = (int)2e9;
const long long LINF = (long long)2e18;
const int MOD = (int)1e9 + 7;
const int MAXN = (int)1;
map<string, int> det;
int determine(string s) {
  while (s.size() < 6) s = ' ' + s;
  int m = s.size();
  string suf;
  for (int i = 1; i <= 6; i++) {
    suf += s[m - i];
    if (det[suf]) return det[suf];
  }
  return -1;
}
vector<int> v;
void ex() {
  cout << "NO";
  exit(0);
}
int main() {
  ios_base::sync_with_stdio(false);
  det["soil"] = 1;
  det["rte"] = 2;
  det["sitini"] = 3;
  det["alail"] = 4;
  det["arte"] = 5;
  det["setini"] = 6;
  string word;
  int c1 = 0, c2 = 0;
  bool fl = false;
  while (cin >> word) {
    int x = determine(word);
    c1 += (1 <= x && x <= 3);
    c2 += (4 <= x && x <= 6);
    if (x == -1) {
      fl = true;
    }
    if (x > 3) x -= 3;
    v.push_back(x);
  }
  if (c1 && c2) {
    ex();
  }
  if (fl) {
    ex();
  }
  if (v.size() > 1 && v.back() == v[0]) {
    ex();
  }
  for (int i = 1; i < v.size(); i++) {
    if (v[i] < v[i - 1]) {
      ex();
    }
    if (v[i] == 2 && v[i - 1] == 2) {
      ex();
    }
    if (v[i] - v[i - 1] > 1) {
      ex();
    }
  }
  cout << "YES";
}
