#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  int count = 0;
  for (int i = 0; i < s.size(); ++i) {
    (int(s[i]) < 96) ? ++count : --count;
  }
  if (count > 0) {
    for (int i = 0; i < s.size(); ++i) s[i] = toupper(s[i]);
    cout << s;
  } else {
    for (int i = 0; i < s.size(); ++i) s[i] = tolower(s[i]);
    cout << s;
  }
}
