#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
void err(istream_iterator<string> it) {}
template <typename T, typename... Args>
void err(istream_iterator<string> it, T a, Args... args) {
  cerr << *it << " = " << a << endl;
  err(++it, args...);
}
template <class T, class U>
inline void checkmin(T &x, U y) {
  if (y < x) x = y;
}
template <class T, class U>
inline void checkmax(T &x, U y) {
  if (y > x) x = y;
}
template <class T, class U>
inline bool ifmax(T &x, U y) {
  if (y > x) return x = y, true;
  return false;
}
template <class T, class U>
inline bool ifmin(T &x, U y) {
  if (y < x) return x = y, true;
  return false;
}
long long fstpow(long long a, long long b) {
  long long res = 1;
  while (b) {
    if (b & 1) res = (res * a);
    a = (a * a);
    b >>= 1;
  }
  return res;
}
long long powm(long long a, long long b, long long mod) {
  long long res = 1;
  while (b) {
    if (b & 1) res = (res * a) % mod;
    a = (a * a) % mod;
    b >>= 1;
  }
  return res;
}
bool sortinrev(const pair<int, int> &a, const pair<int, int> &b) {
  return (a.first > b.first);
}
void fukof() {}
void problem() {}
const long long mod = 1e9 + 7;
const long long N = 100005;
const long long inf = 1e9;
void solve() {
  long long n;
  cin >> n;
  long long a[n + 1], sum = 0;
  for (long long i = 0; i < (n); i++) cin >> a[i + 1], sum += a[i + 1];
  if (sum < 2 * n - 2) {
    cout << "NO\n";
    return;
  }
  cout << "YES ";
  long long cnt2 = 0, cnt1 = 0;
  vector<long long> a1, a2;
  for (long long i = 0; i < (n); i++) {
    if (a[i + 1] > 1)
      cnt2++, a2.push_back(i + 1);
    else
      cnt1++, a1.push_back(i + 1);
  }
  cout << cnt2 + (cnt1 >= 2 ? 2 : cnt1) - 1 << endl;
  cout << n - 1 << endl;
  if (cnt2 and cnt1) {
    a[a2[0]]--;
    a[a1[0]]--;
    cnt1--;
    cout << a2[0] << " " << a1[0] << endl;
    if (cnt1) {
      a[a2.size() - 1]--;
      a[a1[1]]--;
      cnt1--;
      cout << a2[a2.size() - 1] << " " << a1[1] << endl;
    }
  }
  for (long long i = 0; i < (a2.size() - 1); i++) {
    a[a2[i]]--;
    a[a2[i + 1]]--;
    cout << a2[i] << " " << a2[i + 1] << endl;
  }
  long long ptr = 0, ptr2 = a1.size() - 1;
  while (cnt1 > 0) {
    if (a[a2[ptr]] > 0) {
      a[a2[ptr]]--;
      a[a1[ptr2]]--;
      cout << a2[ptr] << " " << a1[ptr2] << endl;
      ptr2--;
      cnt1--;
    } else
      ptr++;
  }
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0), cout.tie(0);
  cout << fixed << setprecision(15);
  int tc = 1;
  while (tc--) {
    problem();
    fukof();
    solve();
  }
  return 0;
}
