#include <iostream>
#include <vector>
#include <array>
#include <algorithm>
#include <string>
#include <map>
#include <queue>
#include <iomanip>
#include <numeric>
#include <memory>
#include <limits.h>
#include <set>
#include <cassert>
#include <cmath>
#include <bitset>
#include <functional>
#include <limits>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;

#define REP(i,n) for(ll i=0; i<(n); ++i)
#define TEN(x) ((ll)1e##x)
#define ALL(v) (v).begin(), (v).end()

// エラトステネスのふるい O(n log log n) : t[i] = true ⇔ iが素数 (i <= n)
vector<int> sieve_of_eratosthenes(ll n) {
	vector<int> t(n+1, true); t[0] = t[1] = false;
	for(ll i = 2; i <= n; ++i) if (t[i]){
		for(ll j = 2*i; j <= n; j += i) t[j] = false;
	}
	return t;
}

vector<ll> get_occur_list(ll x) {
	vector<ll> occur(10, 0);
	while (x!=0) {
		occur[x % 10]++;
		x /= 10;
	}
	return occur;
}

int main(){
	vector<bool> a(10, false);
	ll n; cin >> n;
	REP(_, n) {
		ll i; cin >> i;
		a[i] = true;
	}
	
	vector<ll> p; p.reserve(5000000);
	{
		auto t = sieve_of_eratosthenes(5000000);
		REP(i, t.size()) if (t[i]) p.push_back(i);
	}

	ll max_interval = -1;
	vector<ll> occur(10, 0);
	ll end = -1;
	REP(i, p.size()) {
		auto _ = get_occur_list(p[i]);
		REP(j, 10) occur[j] += _[j];
		REP(j, 10) if(!a[j]) while(occur[j]!=0){
			end++;
			auto _ = get_occur_list(p[end]);
			REP(k, 10) occur[k] -= _[k];
		}

		bool valid = true;
		REP(j, 10) if (a[j]) if (occur[j] == 0) valid = false;
		if (valid) {
			ll k = (end == -1) ? 1 : p[end] + 1 ;
			ll l = (i == p.size() - 1) ? 5000000 : p[i+1] - 1 ;
			max_interval = max(max_interval, l - k);
		}
	}
	cout << max_interval << endl;
	return 0;
}