//#include <tourist>
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> p;
const int INF = 1e9;
const ll LINF = ll(1e18);
const int MOD = 1000000007;
const int dx[4] = {0, 1, 0, -1}, dy[4] = {-1, 0, 1, 0};
const int Dx[8] = {0, 1, 1, 1, 0, -1, -1, -1}, Dy[8] = {-1, -1, 0, 1, 1, 1, 0, -1};
#define yes cout << "Yes" << endl
#define YES cout << "YES" << endl
#define no cout << "No" << endl
#define NO cout << "NO" << endl
#define rep(i, n) for (int i = 0; i < n; i++)
#define ALL(v) v.begin(), v.end()
#define debug(v)          \
    cout << #v << ":";    \
    for (auto x : v)      \
    {                     \
        cout << x << ' '; \
    }                     \
    cout << endl;
template <class T>
bool chmax(T &a, const T &b)
{
    if (a < b)
    {
        a = b;
        return 1;
    }
    return 0;
}
template <class T>
bool chmin(T &a, const T &b)
{
    if (b < a)
    {
        a = b;
        return 1;
    }
    return 0;
}
//cout<<fixed<<setprecision(15);有効数字15桁
//-std=c++14
//-std=gnu++17
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }
int n;
vector<int> a;
//エラトステネスの篩
vector<bool> sieve(int n)
{
    vector<bool> isp(n + 1, true);
    isp[0] = false;
    isp[1] = false;
    for (int i = 2; pow(i, 2) <= n; i++)
    {
        if (isp[i])
            for (int j = 2; i * j <= n; j++)
                isp[i * j] = false;
    }
    return isp;
}
void change(vector<int> &count, int k, int dx)
{
    while (k)
    {
        count[k % 10] += dx;
        k /= 10;
    }
}
int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    cin >> n;
    vector<bool> must(10, false);
    for (int i = 0; i < n; i++)
    {
        int temp;
        cin >> temp;
        a.push_back(temp);
        must[temp] = true;
    }
    vector<bool> isp = sieve(5000000);
    vector<int> count(10, 0);
    int i = 1;
    int j = 1;
    int ans = -1;
    while (j <= 5000000)
    {
        if (isp[j])
        {
            change(count, j, 1);
        }
        bool check = false;
        do
        {
            rep(k, 10)
            {
                if (!must[k] && count[k])
                { //余分なのがいる
                    check = true;
                }
            }
            if (check)
            {
                while (!isp[i] && i < j)
                    i++;
                change(count, i, -1); //左の素数の分引く
                i++;
            }
        } while (check && i < j);
        //余分な数字はなくなりました
        bool check1 = true;
        rep(k, 10)
        {
            if (must[k] && !count[k])
            {
                check1 = false; //必要なものがない
            }
        }
        if (check1)
        {
            chmax(ans, j - i);
        }
        j++;
    }
    cout << ans << "\n";
}