#include <bits/stdc++.h>
using namespace std;
const long long mod = 1000000007;
const int N = 100010;
const double pi = acos(-1.0);
long long mypow(long long a, long long e) {
  return e ? (e & 1 ? mypow(a, e - 1) * a % mod : mypow(a * a % mod, e >> 1))
           : 1;
}
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
int readInt() {
  int x;
  scanf("%d", &x);
  return x;
}
int main() {
  string s;
  cin >> s;
  int res1 = 0, res2 = 0;
  for (int i = 0; i < (int)(((int)(s).size())); ++i) {
    if (s[i] >= 'A' && s[i] <= 'Z')
      res2++;
    else
      res1++;
  }
  if (res2 <= res1)
    transform(s.begin(), s.end(), s.begin(), ::tolower);
  else
    transform(s.begin(), s.end(), s.begin(), ::toupper);
  cout << s;
  return 0;
}
