#include <bits/stdc++.h>
using namespace std;
bool is_lower(char c) { return c >= 'a' && c <= 'z'; }
bool is_upper(char c) { return c >= 'A' && c <= 'Z'; }
int main() {
  char s[200];
  scanf("%s", s);
  int lower_count = 0, upper_count = 0;
  for (int i = 0; s[i]; ++i) {
    if (is_lower(s[i]))
      ++lower_count;
    else
      ++upper_count;
  }
  if (lower_count >= upper_count) {
    for (int i = 0; s[i]; ++i) {
      if (is_lower(s[i]))
        putchar(s[i]);
      else
        putchar(s[i] - 'A' + 'a');
    }
  } else {
    for (int i = 0; s[i]; ++i) {
      if (is_upper(s[i]))
        putchar(s[i]);
      else
        putchar(s[i] - 'a' + 'A');
    }
  }
  puts("");
  return 0;
}
