模拟即可
#include<iostream>
#include<cstdio>
#include<algorithm>
#include<string>
#include<cstring>
#include<queue>
#include<cmath>
#include<set>
#define ll long long
using namespace std;
int main(){
int now=0,n,a;
scanf("%d",&n);
int sum=0;
for(int i=1;i<=n;i++){
scanf("%d",&a);
if(now<a)sum+=6*(a-now);
if(now>a)sum+=4*(now-a);
now=a;
}
sum+=5*n;
printf("%d\n",sum);
}