#include <bits/stdc++.h>
using namespace std;
int main() {
  string word;
  while (getline(cin, word)) {
    int lowerCount = 0, upperCount = 0;
    string lower = "", upper = "";
    for (auto c : word) {
      c == tolower(c) ? lowerCount++ : upperCount++;
      lower += tolower(c);
      upper += toupper(c);
    }
    cout << (lowerCount >= upperCount ? lower : upper) << "\n";
  }
}
