学步园

//the elevator may stay at the same floor several times.
#include<stdio.h>
int main(){
  int i,n,last=0,now,total=0;
  scanf("%d",&n);
  for(i=0;i<n;i++){
    scanf("%d",&now);
    if(now>last){
  total=(now-last)*6+5+total;
  last=now;
    }
    else if(now<last){
  total=(last-now)*4+5+total;
  last=now;
    }
    else{
  total=total+5;
 }
  } 
  printf("%d\n",total);
  return 0; 
}