#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  int cup = 0, cdown = 0;
  for (int i = 0; i < s.size(); i++) {
    if (isupper(s[i]))
      cup++;
    else
      cdown++;
  }
  if (cup > cdown) {
    char ch;
    for (int i = 0; i < s.size(); i++) {
      ch = toupper(s[i]);
      cout << ch;
    }
  } else {
    char ch;
    for (int i = 0; i < s.size(); i++) {
      ch = tolower(s[i]);
      cout << ch;
    }
  }
  return 0;
}
