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

#define RREP(i,s,e) for (i = e-1; i >= s; i--)
#define rrep(i,n) RREP(i,0,n)
#define REP(i,s,e) for (i = s; i < e; i++)
#define rep(i,n) REP(i,0,n)
#define INF 1e8

typedef long long ll;

int main() {
    string s, strs[50];
    int w[50] {};
    int i, n {}, si {};
    bool wara = false;
    cin >> s;
    for (i = 0; i < s.size(); i+=n) {
        unsigned char c = s[i];
        n = 1 + (c >= 0x80) + (c >= 0xE0) + (c >= 0xF0);
        if (s.compare(i,n,"ｗ") == 0) {
            wara = true;
            w[si]++;
        }
        else {
            if (wara) {
                if (strs[si] != "")
                    si++;
                else {
                    strs[si] = "";
                    w[si] = 0;
                }
            }
            wara = false;
            strs[si] += s.substr(i,n);
        }
    }
    int mx = *max_element(w,w+50);
    if (mx == 0)
        cout << endl;
    else {
        rep (i,50) {
            if (w[i] == mx && strs[i] != "")
                cout << strs[i] << endl;
        }
    }
    return 0;
}