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