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