#include<bits/stdc++.h>
using namespace std;
int n,a[20000005],sum;
int main(){
    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>a[i];
    }
    sort(a+1,a+1+n);
    sum+=6*a[1]+6;
    for(int i=2;i<=n;i++){
        if(a[i]==a[i+1]) sum++;
        else if(a[i]<a[i+1]){
        sum+=(a[i+1]-a[i])*6+6;
         }else sum+=(a[i]-a[i+1])*4+6;
    }
    sum+=(a[n]-0)*4;
        cout<<sum;
	return 0;
}

想了n个小时？