#include <bits/stdc++.h>
using namespace std;
int main() {
  char a[110] = " ";
  int i;
  int upper = 0, lower = 0;
  cin >> a;
  for (i = 0; i < strlen(a); i++) {
    if (a[i] >= 'A' && a[i] <= 'Z') {
      upper++;
    }
    if (a[i] >= 'a' && a[i] <= 'z') {
      lower++;
    }
  }
  if (upper > lower) {
    for (i = 0; i < strlen(a); i++) {
      if (a[i] > 'Z') {
        a[i] = a[i] - 32;
      }
    }
  } else if (lower >= upper) {
    for (i = 0; i < strlen(a); i++) {
      if (a[i] < 'a') {
        a[i] = a[i] + 32;
      }
    }
  }
  for (i = 0; i < strlen(a); i++) {
    cout << a[i];
  }
}
