#include <bits/stdc++.h>
using namespace std;
int main() {
  string q;
  cin >> q;
  string Q = q;
  double n = q.size();
  for (int i = 0; i < n; i++) {
    Q[i] = toupper(q[i]);
  }
  int x = 0;
  for (int i = 0; i < n; i++) {
    if (q[i] != Q[i]) {
      x++;
    }
  }
  if (x < n / 2.0) {
    cout << Q;
  } else {
    for (int i = 0; i < n; i++) {
      q[i] = tolower(q[i]);
    }
    cout << q;
  }
  return 0;
}
