#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  int c1 = 0, c2 = 0;
  cin >> s;
  for (int i = 0; i < s.size(); i++) {
    if (isupper(s[i])) {
      c1++;
    } else if (islower(s[i])) {
      c2++;
    }
  }
  if (c1 > c2) {
    for (size_t i = 0; i < s.length(); i++) {
      s[i] = toupper(s[i]);
    }
  } else {
    for (size_t i = 0; i < s.length(); i++) {
      s[i] = tolower(s[i]);
    }
  }
  cout << s;
  return 0;
}
