#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  int n;
  cin >> n;
  vector<int> a(n);
  rep(i, n) cin >> a[i];
  vector<int> cnt(10, 0);
  rep(i, n) cnt[a[i]]++;
  vector<int> rem, us;
  rep(i, 10) {
    if (cnt[i] % 2 == 1) rem.push_back(i);
    if (cnt[i] >= 2) us.push_back(i);
  }
  int ans = 1e9;
  int minim = us.empty() ? 0 : *min_element(us.begin(), us.end());
  do {
    int x = 0, y = 0;
    if (rem.size() % 2 == 1) y = minim;
    rep(i, rem.size()) {
      if (i < rem.size() / 2)
        x = x * 10 + rem[i];
      else
        y = y * 10 + rem[i];
    }
    ans = min(ans, abs(x - y));
  } while (next_permutation(rem.begin(), rem.end()));
  cout << ans << '\n';
  return 0;
}