[HNOI2002]营业额统计

set大法好
(颓)

//Writer : Hsz %WJMZBMR%tourist%hzwer
#include <iostream>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <queue>
#include <map>
#include <set>
#include <stack>
#include <cctype>
#include <vector>
#include <cstdlib>
#include <algorithm>
#define LL long long
#define M(a,b) memset(a,b,sizeof a)
using namespace std;
const int inf=0x3fffffff;
LL in()
{
	LL x=0,f=1;
	char ch=getchar();
	while(ch<'0'||ch>'9') {
		if(ch=='-')f=-1;
		ch=getchar();
	}
	while(ch>='0'&&ch<='9') {
		x=(x<<3)+(x<<1)+ch-'0';
		ch=getchar();
	}
	return x*f;
}
void out(int x)
{
	int a[25],wei=0;
	if(x<0) putchar('-'),x=-x;
	for(; x; x/=10) a[++wei]=x%10;
	if(wei==0) {
		puts("0");
		return;
	}
	for(int j=wei; j>=1; --j) putchar('0'+a[j]);
	putchar('\n');
}
int n;
LL sum,t;
set<int> s;
set<int>::iterator s1;
int main()
{
	n=in();
	sum=in();
	s.insert(sum);
 	for(int i=2; i<=n; i++) {
		t=in();
		s1=s.lower_bound(t);
		LL tp=inf;
		if(s1!=s.end()) tp=min(tp,abs((*s1)-t));
		if(s1!=s.begin()) tp=min(tp,abs((*--s1)-t));
		sum+=tp;
		s.insert(t);
	}
	out(sum);
	return 0;
}