#include<iostream>
#include<vector>

using namespace std;

class liczba
{
    private:
     int first;
     int second;
     int diff;

    public:

    liczba(int _first, int _second)
    {
        first = _first;
        second = _second;
        diff = first - second;
    }

    int getDiff()
    {
        return diff;
    }

    int getFirst()
    {
        return first;
    }

    int getSecond()
    {
        return second;
    }
};

int main()
{
    int n;
    vector<liczba> results;


    cin >> n;
    results.reserve(n/2);

    int * tb = new int[n];

    for(int i = 0; i < n; i ++)
    {
        cin >> tb[i];
    }



    for(int i = 0; i < n; i ++)
    {

        for(int j = 0; j < n; j ++)
        {



            if(tb[i] > tb[j])
            {
                if(results.empty())
                 {
                    liczba l (tb[i],tb[j]);
                    results.push_back(l);
                 }

                if(results.at(0).getDiff() > (tb[i] - tb[j]))
                {
                    results.clear();
                    liczba l (tb[i],tb[j]);
                    results.push_back(l);
                }
                else if(results.at(0).getDiff() == (tb[i] - tb[j]) && (results.at(0).getFirst() != tb[i]) && (results.at(0).getSecond() != tb[j]) )
                {
                    liczba l (tb[i],tb[j]);
                    results.push_back(l);
                }

            }
        }
    }





    if(results.size() > 0)
    {
        cout << results.at(0).getDiff() << endl;
    }


    for(unsigned int i = 0; i < results.size(); i ++)
    {
          cout << results.at(i).getFirst() << " " << results.at(i).getSecond() <<endl;
    }

    return 0;
}