#include "bits/stdc++.h" using namespace std; #ifdef _DEBUG #include "dump.hpp" #else #define dump(...) #endif #define int long long #define rep(i,a,b) for(int i=(a);i<(b);i++) #define rrep(i,a,b) for(int i=(b)-1;i>=(a);i--) #define all(c) begin(c),end(c) const int INF = sizeof(int) == sizeof(long long) ? 0x3f3f3f3f3f3f3f3fLL : 0x3f3f3f3f; const int MOD = 1'000'000'007; template bool chmax(T &a, const T &b) { if (a < b) { a = b; return true; } return false; } template bool chmin(T &a, const T &b) { if (b < a) { a = b; return true; } return false; } signed main() { cin.tie(0); ios::sync_with_stdio(false); int N, K; cin >> N >> K; vector a(N); rep(i, 0, N) { cin >> a[i]; } sort(all(a)); vector d; rep(i, 0, N - 1) d.push_back(a[i + 1] - a[i]); sort(all(d)); dump(d); int ans = 0; rep(i, 0, N - K) { ans += d[i]; } cout << ans << endl; return 0; }