LINEGAME

#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <cmath>
#include <climits>
#include <set>
using namespace std;
const int N = 1e6;
long long a[N+1], dp[3][N+1], n;
void read()
{
    cin >> n;
    for (int i = 1; i <= n; ++ i)
    {
        cin >> a[i];
    }
}
void solve()
{
    dp[1][0] = 0;
    dp[2][0] = 0;
    for (int i = 1; i <= n; ++ i)
    {
        dp[1][i] = max(dp[1][i-1], dp[2][i-1] + a[i]);
        dp[2][i] = max(dp[2][i-1], dp[1][i-1] - a[i]);
    }
    cout << max(dp[1][n], dp[2][n]);
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    read();
    solve();
}