#include <bits/stdc++.h>
using namespace std;
int main() {
  string str;
  cin >> str;
  int s = 0, c = 0;
  for (int i = 0; i < str.size(); i++) {
    if (str[i] >= 97 && str[i] <= 122)
      s++;
    else if (str[i] >= 65 && str[i] <= 90)
      c++;
  }
  if (s >= c) {
    for (int i = 0; i < str.size(); i++) {
      cout << char(tolower(str[i]));
    }
  } else {
    for (int i = 0; i < str.size(); i++) {
      cout << char(toupper(str[i]));
    }
  }
}
