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