#include <bits/stdc++.h>
using namespace std;
void solve() {
  string s;
  cin >> s;
  long long cnt = 0;
  for (long long i = 0; i < s.length(); i++) {
    if (s[i] >= 97) cnt++;
  }
  if (cnt >= s.length() - cnt) {
    transform(s.begin(), s.end(), s.begin(), ::tolower);
  } else
    transform(s.begin(), s.end(), s.begin(), ::toupper);
  cout << s << endl;
}
int main() {
  long long t = 1;
  while (t--) {
    solve();
  }
}
