#include <bits/stdc++.h>
using namespace std;
int main() {
  int b = 0, a = 0;
  string s;
  getline(cin, s);
  for (int i = 0; i < s.size(); i++) {
    if (s[i] >= 'A' && s[i] <= 'Z')
      b++;
    else
      a++;
    s[i] = toupper(s[i]);
  }
  if (b > a)
    cout << s << endl;
  else {
    for (int i = 0; i < s.size(); i++) {
      char c = s[i] + 32;
      cout << c;
    }
    cout << endl;
  }
  return 0;
}
