#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math")
string s, u, l;
int cnt, n;
int main() {
  cin >> s;
  n = s.size();
  for (int i = 0; i < n; i++) {
    if (s[i] >= 'A' && s[i] <= 'Z') {
      cnt++;
      l += (s[i] - 'A' + 'a');
      u += s[i];
    } else {
      cnt--;
      l += s[i];
      u += (s[i] - 'a' + 'A');
    }
  }
  if (cnt > 0)
    cout << u;
  else
    cout << l;
  return 0;
}
