#include <bits/stdc++.h>
using namespace std;
int main() {
  long long a, b, c, d, e, g = 0, f = 0, y[10000];
  string x;
  cin >> x;
  for (a = 0; a < x.size(); a++) {
    if (x[a] >= 97) {
      g++;
    }
  }
  if (x.size() > 2 * g) {
    for (b = 0; b < x.size(); b++) {
      if (x[b] >= 97) {
        x[b] = x[b] - 32;
      }
    }
  } else {
    for (b = 0; b < x.size(); b++) {
      if (x[b] < 97) {
        x[b] = x[b] + 32;
      }
    }
  }
  cout << x;
}
