#include <bits/stdc++.h>
using namespace std;
int main() {
  int i;
  char word[105];
  int ll;
  int ul;
  scanf("%s", word);
  int len = strlen(word);
  ll = 0;
  ul = 0;
  for (i = 0; i < len; i++) {
    if (word[i] >= 'a' && word[i] <= 'z') {
      ll++;
    } else if (word[i] >= 'A' && word[i] <= 'Z') {
      ul++;
    }
  }
  char c;
  for (i = 0; i < len; i++) {
    if (ll >= ul) {
      c = tolower(word[i]);
    } else if (ul > ll) {
      c = toupper(word[i]);
    }
    cout << c;
  }
  cout << endl;
  return 0;
}
