#include <bits/stdc++.h>
int main() {
  char s[100];
  int i, upper = 0, lower = 0;
  gets(s);
  for (i = 0; i < strlen(s); i++) {
    if (s[i] >= 'a' && s[i] <= 'z') {
      lower++;
    } else
      upper++;
  }
  if (lower == upper) {
    for (i = 0; i < strlen(s); i++) {
      if (s[i] >= 65 && s[i] <= 90) s[i] = s[i] + 32;
    }
  } else if (lower > upper) {
    for (i = 0; i < strlen(s); i++) {
      if (s[i] >= 65 && s[i] <= 90) s[i] = s[i] + 32;
    }
  } else if (lower < upper) {
    for (i = 0; i < strlen(s); i++) {
      if (s[i] >= 97 && s[i] <= 122) s[i] = s[i] - 32;
    }
  }
  printf("%s", s);
}
