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