1 #include <bits/stdc++.h> 2 #define rep(i,a,b) for(int i = a;i <= b;++ i) 3 #define per(i,a,b) for(int i = a;i >= b;-- i) 4 #define mem(a,b) memset((a),(b),sizeof((a))) 5 #define FIN freopen("in.txt","r",stdin) 6 #define IO ios_base::sync_with_stdio(0),cin.tie(0) 7 #define pb push_back 8 #define mid ((l+r)>>1) 9 #define ls (id<<1) 10 #define rs ((id<<1)|1) 11 using namespace std; 12 typedef long long LL; 13 typedef pair<int, LL> PIR; 14 const int N = 1e5+5; 15 16 int n; 17 LL a[N], sum1[N], sum2[N]; 18 19 int main() 20 {IO; 21 //FIN; 22 cin >> n; 23 rep(i, 1, n) cin >> a[i]; 24 rep(i, 1, n-1) sum1[i] = sum1[i-1]+abs(a[i+1]-a[i])*((i-1)&1?-1:1); 25 rep(i, 1, n-1) sum2[i] = sum2[i-1]+abs(a[i+1]-a[i])*((i-1)&1?1:-1); 26 LL ans = -1e9, minn = 1e9; 27 rep(i, 1, n-1){ 28 ans = max(ans, max(sum1[i], sum1[i]-minn)); 29 minn = min(minn, sum1[i]); 30 } 31 minn = 1e9; 32 rep(i, 1, n-1){ 33 ans = max(ans, max(sum2[i], sum2[i]-minn)); 34 minn = min(minn, sum2[i]); 35 } 36 cout << ans << endl; 37 return 0; 38 }