#include <bits/stdc++.h>
using namespace std;
const int N = 100000;
const int inf = (int)1e9 + 1;
const long long big = (long long)1e18 + 1;
const int P = 31;
const int MOD = (int)1e9 + 7;
const int MOD1 = (int)1e9 + 9;
const double eps = 1e-9;
const double pi = atan2(0, -1);
const int ABC = 26;
int main() {
  string s;
  cin >> s;
  int uppcount = 0;
  int lowcount = 0;
  for (int i = 0; i < s.length(); i++)
    if (s[i] >= 'A' && s[i] <= 'Z')
      uppcount++;
    else if (s[i] >= 'a' && s[i] <= 'z')
      lowcount++;
  if (uppcount > lowcount)
    transform(s.begin(), s.end(), s.begin(), ::toupper);
  else
    transform(s.begin(), s.end(), s.begin(), ::tolower);
  cout << s << endl;
  return 0;
}
