#include <bits/stdc++.h>
using namespace std;
char s1[101];
int cnt[1000];
int main() {
  scanf("%s", s1);
  int lower = 0;
  int upper = 0;
  for (int i = 0; i < strlen(s1); i++) {
    if (s1[i] == tolower(s1[i]))
      lower++;
    else
      upper++;
  }
  if (upper > lower) {
    for (int i = 0; i < strlen(s1); i++) {
      printf("%c", toupper(s1[i]));
    }
  } else {
    for (int i = 0; i < strlen(s1); i++) {
      printf("%c", tolower(s1[i]));
    }
  }
  cout << endl;
}
