//g++ filename.cpp -std=c++14 -DH

#ifdef H
#include "/Users/michaelw/stdc++.h"
#else
#include <bits/stdc++.h>
#endif

using namespace std;

#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()
#define MOD 1e9 + 7

typedef long long ll;
typedef pair<int, string> pis;
typedef pair<int,int> pii;

//set tab size to 3

int main(){
    //codeforces cin
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    ifstream fin("filename.in");
    ofstream fout("filename.out");
    int n;
    cin >> n;
    vector<int> v(n);
    int s = 1, end = 1000000, count = 0;
    for(int i = 0; i < n; i++){
        cin >> v[i];
    }
    int i = 0, j = v.size()-1;
    while(i <= j){
        while(s >= v[i] && i < v.size()){
            // cout << "s " << s << " " << v[i] << endl;
            i++;
        }
        while(end <= v[j] && j >= 0){
            // cout << "end " << end << " " << v[j] << endl;
            j--;
        }
        if(i > j) break;
        // cout << "s " << s << " " << v[i] << endl;
        // cout << "end " << end << " " << v[j] << endl;

        if(v[i] - s < end - v[j]){
            count += abs(v[i] - s);
            end -= abs(v[i] - s);
            s = v[i];
        }
        else{
            count += abs(end - v[j]);
            s += abs(end - v[j]);
            end = v[j];
        }
        // cout << "afters " << s << " " << i << endl;
        // cout << "afterend " << end << " " << j <<endl;

    }
    cout << count << endl;

}