#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  int upper(0), lower(0);
  for (size_t i = 0; i < s.length(); ++i) {
    if (isupper(s[i])) {
      upper += 1;
    } else {
      lower += 1;
    }
  }
  if (upper > lower) {
    for (size_t i = 0; i < s.length(); ++i) {
      s[i] = toupper(s[i]);
    }
  } else {
    for (size_t i = 0; i < s.length(); ++i) {
      s[i] = tolower(s[i]);
    }
  }
  cout << s << endl;
  return 0;
}
