#include <bits/stdc++.h>
using namespace std;
int main() {
  string word;
  cin >> word;
  int upcase = 0;
  int lowcase = 0;
  for (int x = 0; x < word.size(); x++) {
    if (word[x] <= 'Z') {
      upcase++;
    }
    if (word[x] >= 'a') {
      lowcase++;
    }
  }
  if (lowcase >= upcase) {
    for (int z = 0; z < word.size(); z++) {
      if (word[z] <= 'Z') {
        word[z] = word[z] + 32;
      }
    }
  } else {
    for (int y = 0; y < word.size(); y++) {
      if (word[y] >= 'a') {
        word[y] = word[y] - 32;
      }
    }
  }
  cout << word << endl;
  return 0;
}
