#include <bits/stdc++.h>
using namespace std;
int main() {
  int i = 0, a = 0, b = 0;
  string s;
  cin >> s;
  while (s[i] != '\0') {
    if (s[i] >= 65 && s[i] <= 90) {
      a++;
    } else if (s[i] >= 97 && s[i] <= 122)
      b++;
    i++;
  }
  i = 0;
  if (a > b) {
    while (s[i] != '\0') {
      s[i] = toupper(s[i]);
      i++;
    }
  } else if (a < b) {
    while (s[i] != '\0') {
      s[i] = tolower(s[i]);
      i++;
    }
  } else if (a == b) {
    while (s[i] != '\0') {
      s[i] = tolower(s[i]);
      i++;
    }
  }
  cout << s;
  return 0;
}
