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

typedef long long ll;
#define REP(i,n) for(int i=0,_n=(int)(n);i<_n;++i)
#define ALL(v) (v).begin(),(v).end()
#define CLR(t,v) memset(t,(v),sizeof(t))
template<class T1,class T2>ostream& operator<<(ostream& os,const pair<T1,T2>&a){return os<<"("<<a.first<<","<<a.second<< ")";}
template<class T>void pv(T a,T b){for(T i=a;i!=b;++i)cout<<(*i)<<" ";cout<<endl;}
template<class T>void chmin(T&a,const T&b){if(a>b)a=b;}
template<class T>void chmax(T&a,const T&b){if(a<b)a=b;}

ll nextLong() { ll x; scanf("%lld", &x); return x;}

const int MAX_N = 1005;
const int MAX_H = 20004;
ll dp[MAX_N][MAX_H];

int main2() {
  int N = nextLong();
  vector<ll> a(N);
  REP(i, N) a[i] = nextLong();

  const ll INF = 1001001001;
  REP(i, MAX_N) REP(j, MAX_H) dp[i][j] = INF;
  dp[0][0] = 0;
  REP(i, N) {
    REP(j, MAX_H - 1) chmin(dp[i][j+1], dp[i][j]);
    REP(j, MAX_H) {
      chmin(dp[i+1][j], dp[i][j] + abs(a[i] - j));
    }
  }

  ll ans = INF;
  REP(j, MAX_H) chmin(ans, dp[N][j]);
  cout << ans << endl;
  return 0;
}

int main() {

#ifdef LOCAL
  for (;!cin.eof();cin>>ws)
#endif
    main2();
  return 0;
}