#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  int l, d = 0;
  cin >> s;
  l = s.length();
  for (int i = 0; i < l; i++) {
    if (s[i] >= 65 && s[i] <= 90) d++;
  }
  if (d <= l / 2) {
    for (int i = 0; i < l; i++) s[i] = tolower(s[i]);
  } else {
    for (int i = 0; i < l; i++) s[i] = toupper(s[i]);
  }
  cout << s;
}
