#include <bits/stdc++.h>
using namespace std;
template <typename Arg1>
void __f(const char* name, Arg1&& arg1) {
  cerr << name << " : " << arg1 << std::endl;
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args) {
  const char* comma = strchr(names + 1, ',');
  cerr.write(names, comma - names) << " : " << arg1 << " | ";
  __f(comma + 1, args...);
}
int main() {
  string s;
  cin >> s;
  int x = 0, n = s.length();
  for (auto& c : s)
    if (c >= 'a' && c <= 'z') x++;
  __f("x, n - x", x, n - x);
  if (x < n - x) {
    for (auto& c : s)
      if (c >= 'a' && c <= 'z') c = c - 'a' + 'A';
  } else {
    for (auto& c : s)
      if (c >= 'A' && c <= 'Z') c = c + 'a' - 'A';
  }
  cout << s << "\n";
  return 0;
}
