#include <bits/stdc++.h>
using namespace std;
int main() {
  char conten[101];
  int count1 = 0, count2 = 0, i;
  cin >> conten;
  int s = strlen(conten);
  for (i = 0; i <= s; i++) {
    if (conten[i] >= 65 && conten[i] <= 90) {
      count1++;
    }
    if (conten[i] >= 97 && conten[i] <= 122) {
      count2++;
    }
  }
  if (count1 > count2) {
    for (i = 0; i <= s; i++) {
      if (conten[i] >= 97 && conten[i] <= 122) {
        conten[i] -= 32;
      }
    }
  }
  if (count1 <= count2) {
    for (i = 0; i <= s; i++) {
      if (conten[i] >= 65 && conten[i] <= 90) {
        conten[i] += 32;
      }
    }
  }
  cout << conten;
  return 0;
}
