#include <bits/stdc++.h>
using namespace std;
const int T = 100001;
const long long MAX = T;
int n, m, k;
multiset<char> S;
int main(void) {
  string s;
  cin >> s;
  int u = 0;
  int l = 0;
  for (int i = (int)0; i <= (int)s.length() - 1; i++) {
    if (s[i] < 'a') {
      u++;
    } else {
      l++;
    }
  }
  if (u > l) {
    for (int i = (int)0; i <= (int)s.length() - 1; i++) {
      s[i] = toupper(s[i]);
    }
  } else {
    for (int i = (int)0; i <= (int)s.length() - 1; i++) {
      s[i] = tolower(s[i]);
    }
  }
  cout << s << endl;
  return 0;
}
