#include <bits/stdc++.h>
using namespace std;
int main() {
  string x;
  cin >> x;
  int uc = 0, lc = 0;
  for (int i = 0; i < x.size(); i++) {
    if (islower(x[i])) {
      lc++;
    } else
      uc++;
  }
  char c;
  if (lc >= uc) {
    for (int i = 0; i < x.size(); i++) {
      c = tolower(x[i]);
      cout << c;
    }
  } else {
    for (int i = 0; i < x.size(); i++) {
      c = toupper(x[i]);
      cout << c;
    }
  }
}
