#include <bits/stdc++.h>
using namespace std;
int main() {
  string e;
  cin >> e;
  int countMayus = 0, countMinus = 0;
  for (int i = 0; i < e.size(); i++) {
    if (isupper(e[i])) {
      countMayus++;
    } else {
      countMinus++;
    }
  }
  int a = countMayus;
  int b = countMinus;
  if (b > a) {
    for (int i = 0; i < e.size(); i++) {
      cout << char(tolower(e[i]));
    }
  }
  if (a > b) {
    for (int i = 0; i < e.size(); i++) {
      cout << char(toupper(e[i]));
    }
  }
  if (a == b) {
    for (int i = 0; i < e.size(); i++) {
      cout << char(tolower(e[i]));
    }
  }
  return 0;
}
