#include <bits/stdc++.h>
using namespace std;
string word;
int s, c;
int main() {
  cin >> word;
  for (int i = 0; i < word.length(); i++) {
    if (word[i] > 96) s++;
    if (word[i] <= 96) c++;
  }
  for (int i = 0; i < word.length(); i++) {
    if (c > s) {
      if (word[i] > 96) word[i] -= 32;
    } else if (s > c) {
      if (word[i] <= 96) word[i] += 32;
    } else if (s = c) {
      if (word[i] <= 96) word[i] += 32;
    }
  }
  cout << word;
  return 0;
}
