#include <bits/stdc++.h>
using namespace std;
int main() {
  string str;
  cin >> str;
  int n = str.length();
  int u = 0, l = 0;
  for (int i = 0; i < n; i++) {
    if (str[i] >= 'a' && str[i] <= 'z') {
      l++;
    } else if (str[i] >= 'A' && str[i] <= 'Z') {
      u++;
    }
  }
  if (l >= u) {
    for (int i = 0; i < n; i++) {
      str[i] = tolower(str[i]);
      cout << str[i];
    }
  } else {
    for (int i = 0; i < n; i++) {
      str[i] = toupper(str[i]);
      cout << str[i];
    }
  }
  return 0;
}
