#include <bits/stdc++.h>
using namespace std;
void testcase() {
  string s;
  int lower = 0, upper = 0;
  cin >> s;
  for (char i : s) {
    if (i >= 'a' && i <= 'z') {
      lower++;
    } else
      upper++;
  }
  if (lower >= upper) {
    transform(s.begin(), s.end(), s.begin(), ::tolower);
  }
  if (lower < upper) {
    transform(s.begin(), s.end(), s.begin(), ::toupper);
  }
  cout << s;
}
int main() {
  testcase();
  return 0;
}
