#include <bits/stdc++.h>
int main() {
  char a[100];
  int i, j, k, low = 0, high = 0;
  gets(a);
  for (i = 0; a[i] != '\0'; i++) {
    if (a[i] >= 65 && a[i] <= 90)
      high++;
    else
      low++;
  }
  if (high == low) {
    for (i = 0; a[i] != '\0'; i++) {
      if (a[i] >= 65 && a[i] <= 90) a[i] += 32;
    }
  } else if (high > low) {
    for (i = 0; a[i] != '\0'; i++) {
      if (a[i] >= 97 && a[i] <= 122) a[i] -= 32;
    }
  } else if (low > high) {
    for (i = 0; a[i] != '\0'; i++) {
      if (a[i] >= 65 && a[i] <= 90) a[i] += 32;
    }
  }
  puts(a);
  return 0;
}
