#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  int sml = 0, big = 0;
  for (int i = 0; i < s.length(); i++) {
    if (s[i] >= 97) {
      sml++;
    } else if (s[i] >= 65) {
      big++;
    }
  }
  if (sml >= big) {
    for (int i = 0; i < s.length(); i++) {
      s[i] = tolower(s[i]);
    }
  } else {
    for (int i = 0; i < s.length(); i++) {
      s[i] = toupper(s[i]);
    }
  }
  cout << s;
}
