#include <bits/stdc++.h>
using namespace std;
int main() {
  char a[1000];
  int i = 0, lower = 0, upper = 0;
  cin >> a;
  int len = strlen(a);
  while (a[i] != 0) {
    if (a[i] >= 'a' && a[i] <= 'z') {
      lower++;
      i++;
    } else if (a[i] >= 'A' && a[i] <= 'Z') {
      upper++;
      i++;
    } else
      i++;
  }
  if (upper > lower) {
    for (i = 0; i < len; i++) {
      if (a[i] >= 97 && a[i] <= 122) {
        a[i] = a[i] - 32;
      }
    }
    cout << a;
  } else {
    for (i = 0; i < len; i++) {
      if (a[i] >= 65 && a[i] <= 92) {
        a[i] = a[i] + 32;
      }
    }
    cout << a;
  }
  return 0;
}
