#include <bits/stdc++.h>
using namespace std;
char s[105];
int cl = 0, cu = 0;
int main() {
  scanf("%s", &s);
  int l = strlen(s);
  for (int i = 0; i < l; i++) {
    if (s[i] < 'a')
      cu++;
    else
      cl++;
  }
  if (cu > cl)
    transform(s, s + l, s, ::toupper);
  else
    transform(s, s + l, s, ::tolower);
  printf("%s\n", s);
  return 0;
}
