#include <bits/stdc++.h>
using namespace std;
int main() {
  string str;
  cin >> str;
  int upper = 0, lower = 0;
  for (int i = 0; i < str.size(); i++) {
    if (str[i] >= 'A' && str[i] <= 'Z')
      upper++;
    else if (str[i] >= 'a' && str[i] <= 'z')
      lower++;
  }
  if (lower < upper) {
    transform(str.begin(), str.end(), str.begin(), ::toupper);
    cout << str << endl;
  } else {
    transform(str.begin(), str.end(), str.begin(), ::tolower);
    cout << str << endl;
  }
  return 0;
}
