#include <bits/stdc++.h> using namespace std; typedef pair<int, int> ii; #define ll long long #define ull unsigned long long #define FOR(i, a, b) for (__typeof(b) i = a; i <= b; i++) #define FOD(i, a, b) for (__typeof(b) i = b; i >= a; i--) #define faster ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0); #define BUG(x) \ { cout << #x << " = " << x << '\n'; } #define PR(x, a, b) \ { \ cout << #x << " = "; \ FOR(i, a, b) cout << x[i] << ' '; \ cout << '\n'; \ } #define sx(a) sort(a + 1, a + 1 + n) #define sz(x) ((int)(x).size() - 1) #define pb push_back #define ii pair<int, int> #define X first #define Y second #define ii pair<int, int> #define vt vector int n; const int MAXN = 1e6 + 2, INF = 1e9; int a[MAXN]; ll d1[MAXN], d2[MAXN]; void solve() { cin >> n; FOR(i, 1, n) cin >> a[i]; // d1[i] ++ // d2[i] -- // tai i, xet phan tu dung truoc FOR(i, 1, n) { d1[i] = max(d1[i - 1], d2[i - 1] - (ll)a[i]); d2[i] = max(d2[i - 1], d1[i - 1] + (ll)a[i]); } cout << max(d1[n], d2[n]); } int main() { faster; solve(); return 0; }