Zadatak Trener - honi-2013-2014-1

/*
    Zadatak: Trener
             http://bit.ly/honi-2013-2014-1

    Datum: 2013-09-28

    Autor zadatka: HSIN/HONI

    Autor rješenja: Kristijan Burnik, udruga informaticara Božo Težak

    Gmail: kristijanburnik

*/

#include <iostream>

using namespace std;

int hist[256]={0};

int main() {

    int n;

    cin >> n;

    for (int i = 0 ; i < n; i++) {
        string s;
        cin >> s;
        hist[ (int) s.c_str()[0] ]++;
    }


    bool found = false;
    for (char c = 'a' ; c <= 'z'; c++) {
        if ( hist[c] >= 5 ) {
            found = true;
            cout << c;
        }
    }

    if (!found)
        cout << "PREDAJA";


    cout << endl;
    return 0;
}