#include <bits/stdc++.h>
using namespace std;
int main() {
  string s, res = "";
  cin >> s;
  int upper = 0, lower = 0;
  for (char d : s) {
    if (isupper(d))
      upper++;
    else
      lower++;
  }
  if (lower >= upper)
    for (char d : s) res += tolower(d);
  else
    for (char d : s) res += toupper(d);
  cout << res;
  return 0;
}
