#include <bits/stdc++.h>
int main() {
  int x, y, z, i, j;
  int count = 0, count1 = 0;
  char str[10001];
  scanf("%s", str);
  x = strlen(str);
  for (i = 0; str[i] != '\0'; i++) {
    if (str[i] >= 'A' && str[i] <= 'Z') {
      count++;
    } else {
      count1++;
    }
  }
  if (count > count1) {
    for (i = 0; str[i] != '\0'; i++) {
      if (str[i] >= 'a' && str[i] <= 'z') {
        str[i] = str[i] - 32;
      }
    }
  } else if (count <= count1) {
    for (i = 0; str[i] != '\0'; i++) {
      if (str[i] >= 'A' && str[i] <= 'Z') {
        str[i] = str[i] + 32;
      }
    }
  }
  puts(str);
  return 0;
}
