#include <bits/stdc++.h>
using namespace std;
string tolower_s(string s) {
  for (auto& c : s) c = tolower(c);
  return s;
}
string toupper_s(string s) {
  for (auto& c : s) c = toupper(c);
  return s;
}
string case_fix(string str) {
  int n_upper = 0;
  int n_lower = 0;
  for (auto& c : str) {
    if (c >= 'a' && c <= 'z') n_lower++;
    if (c >= 'A' && c <= 'Z') n_upper++;
  }
  if (n_upper <= n_lower)
    return tolower_s(str);
  else
    return toupper_s(str);
}
int main(int argc, char* argv[]) {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  string str;
  cin >> str;
  cout << case_fix(str) << endl;
  return 0;
}
