#include<cstdio>#include<iostream>#include<string>#include<string.h>#include<algorithm>#include<queue>#include<map>#include<set>using namespace std;int main(){	//freopen("input.txt","r",stdin);	int n;	cin>>n;	int a[100100];	a[0]=0;	for(int i=1;i<=n;i++)	{		cin>>a[i];	}	int sum=0;	for(int i=1;i<=n;i++)	{		if(a[i]>=a[i-1])			sum+=(a[i]-a[i-1])*6+5;		else			sum+=(a[i-1]-a[i])*4+5;	}	PRintf("%d",sum);	//freopen("con","r",stdin);	system("pause");	return 0;}