codeforces 101341M

#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(LL i = a;i <= b;++ i)
#define per(i,a,b) for(LL i = a;i >= b;-- i)
#define mem(a,b) memset((a),(b),sizeof((a)))
#define FIN freopen("in.txt","r",stdin)
#define IO ios_base::sync_with_stdio(0),cin.tie(0)
#define pb push_back
#define INF 0x3f3f3f3f
#define mod 1000000007
typedef long long LL;
typedef pair<int, int> PIR;
const int N = 2e5+5;

int n, x;
struct Node{
    int id, c;
    Node (int _id, int _c)  { id = _id; c = _c; }
    bool operator < (const Node &r) const { return c < r.c; }
};
vector <Node> v1, v2;
vector <PIR> ans;

int main()
{IO;
    //FIN;
    cin >> n;
    rep(i, 1, n){
        cin >> x;
        if(x == 0)  v2.pb(Node(i, x));
        else v1.pb(Node(i, x));
    }
    sort(v1.begin(), v1.end()); sort(v2.begin(), v2.end());
    int ok = 1;
    rep(i, 0, (int)v1.size()-1){
        if(v2.size() < v1[i].c){
            ok = 0;
            break;
        }
        int cnt = v1[i].c;
        while(cnt){
            ans.pb(PIR(v1[i].id, v2[v2.size()-1].id));
            cnt--;
            v2.pop_back();
        }
        v2.pb(Node(v1[i].id, 0));
    }
    if(!ok) cout << "NO" << endl;
    else{
        cout << "YES" << endl;
        rep(i, 0, (int)ans.size()-1)    cout << ans[i].first << " " << ans[i].second << endl;
    }
    return 0;
}