#include<bits/stdc++.h>
#ifdef _DEBUG
#define ls(x) << x << ", "
#define lv(x) << #x << ": " << flush << x << ", "
#define pr(x) cout << "Line: " << __LINE__ << ", " x << endl;
#else
#define ls(x)
#define lv(x)
#define pr(x) ;
#endif
using namespace std;
typedef unsigned int uint;
bool cmp(uint a, uint b) {
return a > b;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
uint n, k;
cin >> n >> k;
vector<uint> a(n);
for (uint i = 0; i < n; i++) {
cin >> a[i];
}
sort(a.begin(), a.end());
uint last = a[0];
vector<uint> t(n);
uint offset = 0, m = 0;
for (uint i = 0; i < n; i++) {
pr(lv(last) lv(a[i]))
if (last == a[i]) {
offset++;
last = a[i];
continue;
}
t[i - offset] = a[i] - last - 1;
pr(lv(last) lv(a[i] - last - 1))
last = a[i];
m++;
}
t.resize(m);
k--;
sort(t.begin(), t.end(), cmp);
for (uint i = 0; i < m; i++) {
pr(lv(i) lv(t[i]))
}
uint lenght = 0;
for (uint i = k; i < m; i++) {
lenght += t[i];
}
cout << (lenght + n) << '\n';
}
