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