1 //
 2 //by coolxxx
 3 //#include<bits/stdc++.h>
 4 #include<iostream>
 5 #include<algorithm>
 6 #include<string>
 7 #include<iomanip>
 8 #include<map>
 9 #include<memory.h>
10 #include<time.h>
11 #include<stdio.h>
12 #include<stdlib.h>
13 #include<string.h>
14 //#include<stdbool.h>
15 #include<math.h>
16 #define min(a,b) ((a)<(b)?(a):(b))
17 #define max(a,b) ((a)>(b)?(a):(b))
18 #define abs(a) ((a)>0?(a):(-(a)))
19 #define lowbit(a) (a&(-a))
20 #define sqr(a) ((a)*(a))
21 #define swap(a,b) ((a)^=(b),(b)^=(a),(a)^=(b))
22 #define mem(a,b) memset(a,b,sizeof(a))
23 #define eps (1e-8)
24 #define J 10
25 #define mod 1000000007
26 #define MAX 0x7f7f7f7f
27 #define PI 3.14159265358979323
28 #define N 104
29 using namespace std;
30 typedef long long LL;
31 int cas,cass;
32 int n,m,lll,ans;
33 LL aans;
34 double anss;
35 LL a[N];
36 int main()
37 {
38     #ifndef ONLINE_JUDGE
39 //    freopen("1.txt","r",stdin);
40 //    freopen("2.txt","w",stdout);
41     #endif
42     int i,j,k;
43     int x,y;
44 //    for(scanf("%d",&cas);cas;cas--)
45 //    for(scanf("%d",&cas),cass=1;cass<=cas;cass++)
46 //    while(~scanf("%s",s+1))
47     while(~scanf("%d",&n))
48     {
49         for(i=1;i<=n;i++)
50             scanf("%lld",&a[i]);
51         for(i=2;i<n;i++)
52         {
53             if(a[i-1]<a[i] && a[i]>a[i+1])aans+=abs(a[i]-max(a[i-1],a[i+1])),a[i]=max(a[i-1],a[i+1]);
54             else if(a[i-1]>a[i] && a[i]<a[i+1])aans+=abs(a[i]-min(a[i-1],a[i+1])),a[i]=min(a[i-1],a[i+1]);
55         }
56         for(i=2;i<=n;i++)
57             aans+=abs(a[i]-a[i-1]);
58         printf("%lld\n",aans);
59     }
60     return 0;
61 }
62 /*
63 //
64
65 //
66 */