#include <bits/stdc++.h>
using namespace std;
long long gcd(long long a, long long b) { return b == 0 ? a : gcd(b, a % b); }
int main() {
  string str;
  cin >> str;
  int lower = 0, upper = 0;
  for (char i : str) {
    if (islower(i) != 0) {
      lower++;
    } else {
      upper++;
    }
  }
  if (lower >= upper) {
    for (char c : str) printf("%c", tolower(c));
  } else {
    for (char c : str) printf("%c", toupper(c));
  }
  cout << endl;
}
