trener

#include <iostream>

using namespace std;

int t[26];
string v="abcdefghijklmnopqrstuvwxyz";
int main(){
    int n;
    cin >> n;
    string s;
    for(int i=0; i<n; ++i) {
        cin >> s;
        ++t[s[0]-'a'];
    } bool f=0;
    for(int i=0; i<26; ++i) if(t[i]>=5){f=1; cout << v[i];}
    if(!f) cout << "PREDAJA";
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED