#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  int u = 0, l = 0;
  for (int i = 0; i < s.size(); i++) {
    if (s[i] >= 65 && s[i] <= 90)
      u++;
    else
      l++;
  }
  if (l >= u)
    for (int i = 0; i < s.size(); i++) s[i] = tolower(s[i]);
  else
    for (int i = 0; i < s.size(); i++) s[i] = toupper(s[i]);
  cout << s << endl;
}
