模擬即可

#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);
}