13164번

13164

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main()
{
    int n, k;
    vector<int> heights;
    cin >> n >> k;
    for (int i = 0; i < n; i++)
    {
        int height;
        cin >> height;
        heights.push_back(height);
    }

    vector<int> diff;
    for (int i = 1; i < n; i++)
    {
        diff.push_back(heights[i] - heights[i - 1]);
    }

    sort(diff.begin(), diff.end());

    int answer = 0;
    for (int i = 0; i < n - k; i++)
    {
        answer += diff[i];
    }

    cout << answer;
}