#include <bits/stdc++.h>
using namespace std;
long long int n, m, k;
void solve() {
  string s;
  cin >> s;
  int cap = 0, low = 0;
  for (auto x : s) {
    if (x >= 'A' && x <= 'Z')
      cap++;
    else
      low++;
  }
  if (cap > low) {
    for (auto& x : s) {
      if (x >= 'A' && x <= 'Z')
        continue;
      else {
        x = 'A' + (x - 'a');
      }
    }
    cout << s;
  } else {
    for (auto& x : s) {
      if (x >= 'a' && x <= 'z')
        continue;
      else {
        x = 'a' + (x - 'A');
      }
    }
    cout << s;
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  ;
  long long int t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
