#include <bits/stdc++.h>
using namespace std;
int main() {
  string str, str2, str3;
  int count = 0;
  int count2 = 0;
  cin >> str;
  for (int i = 0; i < str.size(); i++) {
    if (str[i] >= 'A' && str[i] <= 'Z')
      count++;
    else if (str[i] >= 'a' && str[i] <= 'z')
      count2++;
  }
  for (int i = 0; i < str.size(); i++) {
    char c = str[i];
    if (count > count2) {
      str2 = toupper(c);
    } else
      str2 = tolower(c);
    str3.append(str2);
  }
  cout << str3 << endl;
  return 0;
}
