#include <bits/stdc++.h>
using namespace std;
int main() {
  int l = 0, u = 0;
  string s;
  cin >> s;
  for (int i = 0; i < s.length(); i++) {
    if (s[i] >= 'A' && s[i] <= 'Z') {
      u = u + 1;
    } else {
      l = l + 1;
    }
  }
  if (l >= u) {
    for (int j = 0; j < s.length(); j++) {
      if (s[j] >= 'A' && s[j] <= 'Z') {
        s[j] = s[j] + 32;
      }
    }
  } else {
    for (int q = 0; q < s.length(); q++) {
      if (s[q] >= 'a' && s[q] <= 'z') {
        s[q] = s[q] - 32;
      }
    }
  }
  cout << s;
}
