#include <bits/stdc++.h>
using namespace std;
signed main() {
  string str;
  cin >> str;
  long long upper = 0;
  long long lower = 0;
  for (long long i = 0; i < str.length(); i++) {
    if (isupper(str[i])) {
      upper++;
    } else {
      lower++;
    }
  }
  if (upper > lower) {
    transform(str.begin(), str.end(), str.begin(), ::toupper);
  } else {
    transform(str.begin(), str.end(), str.begin(), ::tolower);
  }
  cout << str << endl;
}
