#include <bits/stdc++.h>
using namespace std;
int main() {
  string word;
  cin >> word;
  int lowercaseNum = 0;
  for (int i = 0; i < word.length(); i++) {
    if (word[i] >= 'a' && word[i] <= 'z') lowercaseNum++;
  }
  if (word.length() > 2 * lowercaseNum) {
    transform(word.begin(), word.end(), word.begin(), ::toupper);
  } else {
    transform(word.begin(), word.end(), word.begin(), ::tolower);
  }
  cout << word << endl;
}
