#include <bits/stdc++.h>
using namespace std;
int main() {
  int b, i, min = 0, may = 0;
  char a[100];
  cin >> a;
  b = strlen(a);
  for (int i = 0; i < b; i++) {
    if (97 <= a[i] && a[i] <= 122)
      min++;
    else
      may++;
  }
  if (min >= may) {
    for (int i = 0; i < b; i++) {
      if (97 <= a[i] && a[i] <= 122)
        cout << a[i];
      else
        a[i] = a[i] + 32, cout << a[i];
    }
  } else {
    for (int i = 0; i < b; i++) {
      if (97 <= a[i] && a[i] <= 122)
        a[i] = a[i] - 32, cout << a[i];
      else
        cout << a[i];
    }
  }
}
