#include <bits/stdc++.h>
using namespace std;
int main() {
  string word;
  cin >> word;
  int lowerCountner = 0;
  int upperCounter = 0;
  for (int i = 0; i < word.size(); i++) {
    char ch = word[i];
    if (isupper(ch))
      upperCounter++;
    else if (islower(ch))
      lowerCountner++;
  }
  if (lowerCountner >= upperCounter) {
    transform(word.begin(), word.end(), word.begin(), ::tolower);
    cout << word;
  } else {
    transform(word.begin(), word.end(), word.begin(), ::toupper);
    cout << word;
  }
  return 0;
}
