#include <cstdio>
#include <queue>
using namespace std;
const int M = 200005;
#define int long long
int read()
{
	int x=0,f=1;char c;
	while((c=getchar())<'0' || c>'9') {if(c=='-') f=-1;}
	while(c>='0' && c<='9') {x=(x<<3)+(x<<1)+(c^48);c=getchar();}
	return x*f;
}
int n,sh,ans,a[M];priority_queue<int> q;
signed main()
{
	n=read();
	for(int i=1;i<=n;i++)
	{
		a[i]=read();int x=a[i],y=0;
		if(i>1) sh+=max(a[i]-a[i-1],0ll);//tag
		q.push(-sh);q.push(-sh);//insert the change point
		q.push(a[i]-sh);q.push(a[i]-sh);
		q.pop();y=q.top()+sh;q.pop();//pre min
		ans+=2*y-x;//update the 0-slope-line
	}
	printf("%lld\n",ans);
}