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#include<iostream>
#include<algorithm>
using namespace std;

const int ene = 1e6+10;
int t[ene];


int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int n;
    cin >> n;
    for(int i = 0; i < n; i++)
    {
        int a;
        cin >> a;
        a--;
        t[i] = a;
    }
    sort(t,t+n);
    int zera = 0;
    int kraw = 0;
    for(int i = 0; i < n; i++)
    {
        if(t[i] == 0)zera++;
        kraw+=t[i];
        if(kraw == i-1 && i>=2)
        {
            cout << 0 << "\n";
            cout << i+1 << "\n";
            int k = i-1;
            t[i]++;
            for(int j = i; j >= 0; j--)
            {
                for(int h = 0; h < t[j]; h++)
                {
                    cout << j+1 << " " << k+1 << "\n";
                    k--;
                }
            }
            return 0;
        }
        if(kraw > i-1 && i>= 2)
        {
            cout << 1 << "\n" << i+1 << "\n";
            t[i]-=(kraw-i+1);
            int k = i-1;
            t[i]++;
            for(int j = i; j >= 0; j--)
            {
                for(int h = 0; h < t[j]; h++)
                {
                    cout << j+1 << " " << k+1 << "\n";
                    k--;
                }
            }
            return 0;
        }
    }
    return 0;
}