#include <bits/stdc++.h>
using namespace std;
int main() {
  string str;
  cin >> str;
  int len = str.length();
  int lower = 0;
  int upper = 0;
  for (int i = 0; i < len; ++i) {
    if (str[i] < 91)
      upper++;
    else
      lower++;
  }
  if (upper > lower)
    transform(str.begin(), str.end(), str.begin(), ::toupper);
  else
    transform(str.begin(), str.end(), str.begin(), ::tolower);
  cout << str;
}
