#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  int upper = 0, lower = 0;
  cin >> s;
  int size = s.length();
  for (int i = 0; i < size; i++) {
    if ((int)s[i] >= 97) {
      lower++;
    } else {
      upper++;
    }
  }
  if (upper > lower) {
    for (int j = 0; j < size; j++) {
      s[j] = toupper(s[j]);
    }
  } else {
    for (int j = 0; j < size; j++) {
      s[j] = tolower(s[j]);
    }
  }
  cout << s;
}
