#include <bits/stdc++.h>
using namespace std;
int main() {
  int i, cn1 = 0, cn2 = 0;
  string s;
  cin >> s;
  for (i = 0; i < s.length(); i++) {
    if (s[i] >= 'a' && s[i] <= 'z') {
      cn1++;
    } else if (s[i] >= 'A' && s[i] <= 'Z') {
      cn2++;
    }
  }
  if (cn1 >= cn2) {
    for (i = 0; i < s.length(); i++) {
      if (s[i] >= 'a' && s[i] <= 'z') {
        cout << s[i];
      } else if (s[i] >= 'A' && s[i] <= 'Z') {
        s[i] = s[i] + 32;
        cout << s[i];
      }
    }
  } else if (cn2 > cn1) {
    for (i = 0; i < s.length(); i++) {
      if (s[i] >= 'A' && s[i] <= 'Z') {
        cout << s[i];
      } else if (s[i] >= 'a' && s[i] <= 'z') {
        s[i] = s[i] - 32;
        cout << s[i];
      }
    }
  }
  return 0;
}
