#include <bits/stdc++.h>
using namespace std;
int main() {
  string line;
  cin >> line;
  int n = 0, m = 0, l = line.length();
  for (int i = 0; i < l; i++) {
    if (islower(line[i]))
      n++;
    else
      m++;
  }
  if (n >= m) {
    transform(line.begin(), line.end(), line.begin(), ::tolower);
  } else {
    transform(line.begin(), line.end(), line.begin(), ::toupper);
  }
  cout << line;
}
