#include <bits/stdc++.h>
using namespace std;
int main() {
  string a;
  cin >> a;
  int cnt1 = 0;
  int cnt2 = 0;
  for (int i = 0; i < a.size(); i++) {
    if (a[i] >= 'A' && a[i] <= 'Z') {
      cnt1++;
    } else if (a[i] >= 'a' && a[i] <= 'z') {
      cnt2++;
    }
  }
  string b = "";
  if (cnt1 > cnt2) {
    for (int i = 0; i < a.size(); i++) {
      b.push_back(toupper(a[i]));
    }
  } else {
    for (int i = 0; i < a.size(); i++) {
      b.push_back(tolower(a[i]));
    }
  }
  cout << b << endl;
}
