#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  getline(cin, s);
  int m = 0;
  int a = 0;
  for (char& c : s) {
    if (c < 97) {
      a += 1;
    } else {
      m += 1;
    }
  }
  if (a > m) {
    for (char& c : s) {
      c = toupper(c);
    }
  }
  if (m >= a) {
    for (char& c : s) {
      c = tolower(c);
    }
  }
  cout << s << endl;
  return 0;
}
