#include <bits/stdc++.h>
using namespace std;
void convert(string &s) {
  for (int i = 0; i < s.size(); i++) {
    s[i] = toupper(s[i]);
  }
}
void Convert(string &s) {
  for (int i = 0; i < s.size(); i++) {
    s[i] = tolower(s[i]);
  }
}
int main() {
  int c = 0, C = 0, j;
  string s;
  cin >> s;
  int l = s.size();
  for (j = 0; j <= l; j++) {
    if (s[j] >= 65 && s[j] <= 90) {
      C++;
    }
    if (s[j] >= 97 && s[j] <= 122) {
      c++;
    }
  }
  if (C > c) {
    convert(s);
    cout << s << endl;
  } else if (c > C || c == C) {
    Convert(s);
    cout << s << endl;
  }
  return 0;
}
