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