hackathon: "vocale"

#include <bits/stdc++.h>
using namespace std;
const string pairs = "ae ai ao au ea ee ei eo eu ia ie ii io iu oa oe oi ou ua oo ue ui uu uo";
map<string, int> fr;

bool isVowel(char c) {
    return c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u';
}

signed main() {
    //freopen("text.in", "r", stdin);
    string text;
    for (string line; getline(cin, line);) {
        text += line + '\n';
    }

    if (!text.size()) {
        puts(pairs.c_str());
        return 0;
    }

    for (size_t i = 1; i < text.size(); i++) {
        if (isVowel(text[i - 1]) && isVowel(text[i])) {
            string pairOfVowels = string(1, text[i - 1]) + string(1, text[i]);
            fr[pairOfVowels]++;
        }
    }

    int frMax = -1;
    for (const auto &it : fr) {
        frMax = max(frMax, it.second);
    }

    for (const auto &[fi, se] : fr) {
        if (se == frMax) {
            cout << fi << ' ';
        }
    }

    return 0;
}