#include <bits/stdc++.h>
using namespace std;
int main() {
  string sen;
  int large = 0, small = 0;
  cin >> sen;
  for (int i = 0; i < sen.length(); i++) {
    if (sen[i] < 97)
      large++;
    else
      small++;
  }
  if (large > small) {
    for (int i = 0; i < sen.length(); i++) {
      if (sen[i] >= 97) sen[i] -= 32;
    }
  } else {
    for (int i = 0; i < sen.length(); i++) {
      if (sen[i] < 97) sen[i] += 32;
    }
  }
  cout << sen;
}
