#include <bits/stdc++.h>
using namespace std;
int main() {
  int up{0}, lw{0};
  string s;
  cin >> s;
  for (auto x : s) {
    if (isupper(x))
      up++;
    else
      lw++;
  }
  if (up <= lw) {
    for (auto x : s) cout << static_cast<char>(tolower(x));
  } else {
    for (auto x : s) cout << static_cast<char>(toupper(x));
  }
  return 0;
}
