#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  if (s.size() >= 1 && s.size() <= 100) {
    int i, j, k = 0, m = 0;
    for (i = 0; i < s.size(); i++) {
      if (s[i] >= 'a' && s[i] <= 'z') k++;
      if (s[i] >= 'A' && s[i] <= 'Z') m++;
    }
    if (k >= m) {
      for (j = 0; j < s.size(); j++) {
        if (s[j] >= 'A' && s[j] <= 'Z') s[j] = s[j] + 32;
        cout << s[j];
      }
    }
    if (k < m) {
      for (j = 0; j < s.size(); j++) {
        if (s[j] >= 'a' && s[j] <= 'z') s[j] = s[j] - 32;
        cout << s[j];
      }
    }
  }
  return 0;
}
