#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#include "debug.hpp"
#else
#define debug(...) 1
#endif

const int mxY = 10005;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n;
    cin >> n;
    vector<int> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    vector<vector<int>> dp(n + 1, vector<int>(mxY, -(1 << 30)));
    fill(dp[0].begin(), dp[0].end(), 0);
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < mxY; j++) {
            dp[i + 1][j] = dp[i][j] + abs(j - a[i]);
        }
        for (int j = 1; j < mxY; j++) {
            dp[i + 1][j] = min(dp[i + 1][j], dp[i + 1][j - 1]);
        }
    }
    cout << dp[n][mxY - 1] << '\n';
}