#include <bits/stdc++.h>
int main() {
  char str[100];
  scanf("%s", str);
  int count1 = 0;
  int count2 = 0;
  for (int i = 0; str[i] != '\0'; i++) {
    if (str[i] >= 'a' && str[i] <= 'z') {
      count1++;
    }
  }
  for (int i = 0; str[i] != '\0'; i++) {
    if (str[i] >= 'A' && str[i] <= 'Z') {
      count2++;
    }
  }
  if (count1 >= count2) {
    for (int i = 0; str[i] != '\0'; i++) {
      if (str[i] >= 'A' && str[i] <= 'Z') {
        str[i] = str[i] + 32;
      }
    }
  } else {
    for (int j = 0; str[j] != '\0'; j++) {
      if (str[j] >= 'a' && str[j] <= 'z') {
        str[j] = str[j] - 32;
      }
    }
  }
  printf("%s", str);
  return 0;
}
