// #pragma GCC optimize ("Ofast") // #pragma GCC optimize ("unroll-loops") // #pragma GCC target ("avx,avx2,fma") #include using std::cin, std::cout, std::cerr; using ll = long long; int main() { std::ios::sync_with_stdio(false); int n; cin >> n; std::vector a(n); for(int i = 0; i < n; i ++) cin >> a[i]; std::sort(a.begin(), a.end()); std::vector f(n + 1, 1e18L); f[0] = 0; for(int i = 1; i <= n; i ++) { if(i >= 2) f[i] = std::min(f[i], f[i - 2] + a[i - 1] - a[i - 2]); if(i >= 3) f[i] = std::min(f[i], f[i - 3] + a[i - 1] - a[i - 3]); } cout << f[n] << '\n'; }