#include <bits/stdc++.h>
using namespace std;
int main() {
  string a;
  cin >> a;
  int lower = 0, upper = 0;
  for (int i = 0; i < a.size(); i++) {
    if (a[i] >= 'a' && a[i] <= 'z') {
      lower++;
    } else {
      upper++;
    }
  }
  if (lower >= upper) {
    for (int i = 0; i < a.size(); i++) {
      if (a[i] >= 'A' && a[i] <= 'Z') {
        a[i] += 32;
      }
    }
    cout << a;
  } else {
    for (int i = 0; i < a.size(); i++) {
      if (a[i] >= 'a' && a[i] <= 'z') {
        a[i] -= 32;
      }
    }
    cout << a;
  }
}
