#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  int counter1 = 0, counter2 = 0;
  getline(cin, s);
  for (auto i : s) {
    if (islower(i) == 2)
      counter1++;
    else
      counter2++;
  }
  if (counter1 >= counter2)
    for (auto &i : s) i = tolower(i);
  if (counter1 < counter2)
    for (auto &i : s) i = toupper(i);
  cout << s;
}
