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

int main()
{
    int N;   
    cin >> N;
    string Tname;
    vector<string> data(N);
    int counter = 0;

    for(int i = 0; i<N; i++)
    {
        cin >> Tname;
        data[i] = Tname;
    }

    for(int l = 0; l<N; l++)
    {
        int k = 0;
        while(k<l &&  data[l] != data[k])
        {
            k++;
        }
        if(k==l)
        {
        	cout<<l<<" "<<data[l]<<endl;
            counter += 1;
        }

    }
    cout << counter << endl;
    return 0;
}