#include <bits/stdc++.h>
int upper, lower;
std::string word;
int main() {
  std::cin >> word;
  int n = word.size();
  for (int i = 0; i < n; ++i) {
    if (word[i] >= 'A' && word[i] <= 'Z') {
      ++upper;
    } else {
      ++lower;
    }
  }
  if (upper > lower) {
    transform(word.begin(), word.end(), word.begin(), ::toupper);
  } else {
    transform(word.begin(), word.end(), word.begin(), ::tolower);
  }
  std::cout << word << '\n';
}
