#include <bits/stdc++.h>
using namespace std;
using lint = long long;

const lint MOD = 998244353;
const lint INF = (1LL<<60);

lint solve(int N, vector<int> c) {
  sort(c.begin(), c.end());
  lint ans = INF;
  do {
    for (lint i = 0; i < (1<<N); i++) {
      lint a = 0, b = 0;
      for (lint j = 0; j < N; j++) {
        if ((1<<j)&i) a = a*10+c[j];
        else b = b*10+c[j];
      }
      ans = min(ans, abs(a-b));
    }
  } while (next_permutation(c.begin(), c.end()));
  return ans;
}

int main() {
  int N;
  cin >> N;
  vector<int> c(N);
  for (int i = 0; i < N; i++) cin >> c[i];
  cout << solve(N, c) << endl;
}