#include <bits/stdc++.h>
using namespace std;
int main() {
  string str;
  int l, n_u = 0, n_l = 0;
  getline(cin, str);
  l = str.length();
  for (int i = 0; i < l; i++) {
    if (str[i] < 91)
      n_u++;
    else
      n_l++;
  }
  if (n_u > n_l)
    for (int i = 0; i < l; i++) {
      if (str[i] > 90) str[i] = str[i] - 32;
    }
  else
    for (int i = 0; i < l; i++) {
      if (str[i] < 91) str[i] = str[i] + 32;
    }
  cout << str;
  return 0;
}
