#include <bits/stdc++.h>
using namespace std;

const int INF = 1000000007;
const int MaxN = 1005;
const int MaxY = 10005;

int dp[MaxN][MaxY];
int y[MaxY];
int n;

int main() {
  scanf("%d", &n);
  for (int i = 0; i < n; i++) scanf("%d", y+i);
  fill(dp[0], dp[MaxN], INF);
  dp[0][0] = 0;
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < MaxY-1; j++) dp[i][j+1] = min(dp[i][j+1], dp[i][j]);
    for (int j = 0; j < MaxY; j++) dp[i+1][j] = dp[i][j] + abs(j-y[i]);
  }
  printf("%d\n", *min_element(dp[n], dp[n+1]));
}