#include <bits/stdc++.h>
using namespace std;
string s;
long long up, low;
int main() {
  cin >> s;
  for (int i = 0; i < s.length(); i++) {
    if (islower(s[i]))
      low++;
    else
      up++;
  }
  for (int i = 0; i < s.length(); i++)
    if (up > low)
      s[i] = toupper(s[i]);
    else
      s[i] = tolower(s[i]);
  cout << s;
}
