#include <bits/stdc++.h>
int main() {
  char s[100];
  scanf("%s", s);
  int upper = 0;
  int lower = 0;
  for (int i = 0; s[i] != '\0'; i++) {
    if (s[i] >= 97)
      lower++;
    else
      upper++;
  }
  if (lower > upper) {
    for (int j = 0; s[j] != '\0'; j++) {
      if (s[j] < 97) s[j] = s[j] + 32;
    }
  } else if (upper > lower) {
    for (int j = 0; s[j] != '\0'; j++) {
      if (s[j] >= 97) s[j] = s[j] - 32;
    }
  } else if (lower == upper) {
    for (int j = 0; s[j] != '\0'; j++) {
      if (s[j] < 97) s[j] = s[j] + 32;
    }
  }
  printf("%s", s);
  return 0;
}
