#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  int count = 0, count1 = 0;
  cin >> s;
  for (int i = 0; i < s.size(); i++) {
    if (s[i] >= 97 && s[i] <= 122)
      count++;
    else
      count1++;
  }
  if (count >= count1) {
    for (int i = 0; i < s.size(); i++) {
      if (isupper(s[i])) s[i] = s[i] + 32;
    }
  } else {
    for (int i = 0; i < s.size(); i++) {
      if (islower(s[i])) s[i] = s[i] - 32;
    }
  }
  cout << s;
}
