#include <iostream>
#include <cmath>
#include <algorithm>
#include <string>
#include <vector>
#include <map>
#include <unordered_map>
#include <queue>
#include <set>
#include <unordered_set>
#include <complex>
#include <list>
#include <chrono>
#include <random>
#include <stack>
#include <iomanip>
#include <fstream>
using namespace std;
#define endl "\n"
// #define int long long
const int INF = 2 * 1e5 + 5;
const int MOD = 1e9 + 7;
void solve(){
int n;
cin >> n;
vector<int> a(n);
for(int i = 0; i < n; i++){
cin >> a[i];
}
int l = 0, r = n-1, h = 0, sol = 0;
while(true){
// cout << a[l] << " " << a[r] << "| " << sol << endl;
if(l+1 == r) break;
if(a[l+1] < a[r-1]){
l++;
sol += abs(a[l] - h);
h = a[l];
} else {
r--;
sol += abs(a[r] - h);
h = a[r];
}
}
cout << sol << endl;
}
int32_t main(){
ios_base::sync_with_stdio(false); cin.tie(nullptr);
int t = 1;
// cin >> t;
while(t--) solve();
return 0;
}
