#include <bits/stdc++.h>
using namespace std;
int main(int argc, char const *argv[]) {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  string s;
  cin >> s;
  int u = 0, l = 0;
  for (auto c : s) {
    if (c - 'A' < 26)
      u++;
    else
      l++;
  }
  if (u > l) {
    for (auto &i : s) i = toupper(i);
  } else
    for (auto &i : s) i = tolower(i);
  cout << s;
  return 0;
}
