#include <bits/stdc++.h>
using namespace std;
int main() {
  string str;
  int a = 0, b = 0;
  cin >> str;
  for (int i = 0; i < str.length(); i++) {
    if (str[i] > 96 && str[i] < 123) {
      a++;
    } else if (str[i] > 64 && str[i] < 91) {
      b++;
    }
  }
  if (a >= b) {
    for (int i = 0; i < str.length(); i++) {
      if (str[i] > 64 && str[i] < 91) {
        str[i] = str[i] + 97 - 65;
      }
      cout << str[i];
    }
  } else if (a < b) {
    for (int i = 0; i < str.length(); i++) {
      if (str[i] > 96 && str[i] < 123) {
        str[i] = str[i] - 97 + 65;
      }
      cout << str[i];
    }
  }
  return 0;
}
