#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; #if __has_include() #include using namespace atcoder; #endif #define GET_MACRO(_1, _2, _3, NAME, ...) NAME #define _rep(i, n) _rep2(i, 0, n) #define _rep2(i, a, b) for(int i = (int)(a); i < (int)(b); i++) #define rep(...) GET_MACRO(__VA_ARGS__, _rep2, _rep)(__VA_ARGS__) #define all(x) (x).begin(), (x).end() #define rall(x) (x).rbegin(), (x).rend() using i64 = long long; template bool chmin(T& a, const U& b) { return (b < a) ? (a = b, true) : false; } template bool chmax(T& a, const U& b) { return (b > a) ? (a = b, true) : false; } templateistream& operator>>(istream&i,vector&v){rep(j,v.size())i>>v[j];return i;} templatestring join(vector&v){stringstream s;rep(i,v.size())s<<' '<ostream& operator<<(ostream&o,vector&v){if(v.size())o<string join(vector>&vv){string s="\n";rep(i,vv.size())s+=join(vv[i])+"\n";return s;} templateostream& operator<<(ostream&o,vector>&vv){if(vv.size())o< using pq = priority_queue, greater>; int main() { i64 b, n; cin >> b >> n; vector c(n); cin >> c; sort(all(c)); i64 left = c[0]; i64 right = (accumulate(all(c), 0ll) + b) / n + 1; auto calc = [&](i64 p) { i64 ret = 0; rep(i, n) ret += abs(c[i] - p); return ret; }; int cnt = 1000; while(cnt--) { i64 m1 = (left * 2 + right) / 3; i64 m2 = (left + right * 2) / 3; if(calc(m1) > calc(m2)) { left = m1; }else right = m2; } i64 ans = 1e18; rep(i, left, right + 1) { chmin(ans, calc(i)); } cout << ans << endl; return 0; }