#include <bits/stdc++.h>
using namespace std;
const int OO = 1e9;
const double EPS = 1e-9;
template <class T>
void _db(const char* dbStr, T e) {
  cout << dbStr << " = " << e << endl;
}
template <class T, class... L>
void _db(const char* dbStr, T e, L... r) {
  while (*dbStr != ',') cout << *dbStr++;
  cout << " = " << e << ',';
  _db(dbStr + 1, r...);
}
template <class S, class T>
ostream& operator<<(ostream& o, const map<S, T>& v) {
  o << "[";
  int i = 0;
  for (const pair<S, T>& pr : v)
    o << (!i++ ? "" : ", ") << "{" << pr.first << " : " << pr.second << "}";
  return o << "]";
}
template <template <class, class...> class S, class T, class... L>
ostream& operator<<(ostream& o, const S<T, L...>& v) {
  o << "[";
  int i = 0;
  for (const auto& e : v) o << (!i++ ? "" : ", ") << e;
  return o << "]";
}
template <class S, class T>
ostream& operator<<(ostream& o, const pair<S, T>& pr) {
  return o << "(" << pr.first << ", " << pr.second << ")";
}
ostream& operator<<(ostream& o, const string& s) {
  for (const char& c : s) o << c;
  return o;
}
template <class T>
using V = vector<T>;
template <class T>
using VV = V<V<T>>;
template <class T>
using VVV = VV<V<T>>;
using ll = long long;
using pii = pair<int, int>;
using vi = V<int>;
using vii = V<pii>;
using vvi = VV<int>;
using mii = map<int, int>;
using umii = unordered_map<int, int>;
using si = set<int>;
using usi = unordered_set<int>;
int main() {
  ios::sync_with_stdio(false);
  cout.precision(10);
  cin.tie(0);
  int n;
  cin >> n;
  vi a(n + 1);
  vi onesCnt(31), zerosCnt(31);
  for (int i = 1; i <= n; ++i) {
    cin >> a[i];
    for (int j = 0; j < 31; ++j) {
      if (a[i] & (1LL << j)) onesCnt[j]++;
    }
  }
  for (int j = 0; j < 31; ++j) {
    if (n % 2 == 0 && onesCnt[j] % 2 == 1) {
      cout << "NO\n";
      return 0;
    }
  }
  cout << "YES\n";
  V<pair<int, pii>> moves;
  if (n % 2 == 1) {
    for (int i = 1; i + 1 <= n - 1; i += 2)
      moves.push_back(make_pair(n, make_pair(i, i + 1)));
    for (int i = 1; i + 1 <= n - 1; i += 2)
      moves.push_back(make_pair(n, make_pair(i, i + 1)));
  } else {
    for (int i = 1; i + 2 <= n; i += 2)
      moves.push_back(make_pair(i, make_pair(i + 1, i + 2)));
    for (int i = 1; i + 1 <= n - 2; i += 2)
      moves.push_back(make_pair(n, make_pair(i, i + 1)));
  }
  cout << int(moves.size()) << '\n';
  for (auto& move : moves) {
    cout << move.first << " " << move.second.first << ' ' << move.second.second
         << '\n';
  }
  return 0;
}
