#include<bits/stdc++.h>
using namespace std;

vector<long long> a;
vector<long long> b;
long long n,m,aa,ans;

int main(){
	ios::sync_with_stdio(0);
	cin >> n;
	a.push_back(0);
	for(int i=1;i<=n;i++){
		cin >> aa;
		a.push_back(aa);
		if(i!=1){
			long long bb=INT_MAX;
			for(int j=1;j<i;j++){
				bb=min(bb,abs(a[j]-a[i]));
			}
			ans+=bb;
		}else ans+=aa;
		
	}
	cout << ans;
}