#include <bits/stdc++.h>
using namespace std;
int main() {
  int cntb = 0, cnts = 0;
  string s;
  cin >> s;
  for (int i = 0; s[i] != '\0'; i++) {
    if (s[i] >= 65 && s[i] <= 90) {
      cntb++;
    } else if (s[i] >= 97 && s[i] <= 122) {
      cnts++;
    }
  }
  if (cnts >= cntb) {
    for (int i = 0; s[i] != '\0'; i++) {
      if (s[i] >= 65 && s[i] <= 90) {
        s[i] = s[i] + 32;
      }
    }
  } else {
    for (int i = 0; s[i] != '\0'; i++) {
      if (s[i] >= 97 && s[i] <= 122) {
        s[i] = s[i] - 32;
      }
    }
  }
  cout << s;
}
