#include <iostream>
#include <vector>
#include <string>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <algorithm>	// require sort next_permutation count __gcd reverse etc.
#include <cstdlib>	// require abs exit atof atoi 
#include <cstdio>		// require scanf printf
#include <functional>
#include <numeric>	// require accumulate
#include <cmath>		// require fabs
#include <climits>
#include <limits>
#include <cfloat>
#include <iomanip>	// require setw
#include <sstream>	// require stringstream 
#include <cstring>	// require memset
#include <cctype>		// require tolower, toupper
#include <fstream>	// require freopen
#include <ctime>		// require srand
#define rep(i,n) for(int i=0;i<(n);i++)
#define ALL(A) A.begin(), A.end()
/*
	No.12 限定された素数

	エラトステネスの篩 しゃくとり法
*/

using namespace std;

typedef long long ll;
typedef pair<int, int> P;

const int MAX_N = 5000000;

bool p[MAX_N+1];
vector<int> prime;

void sieve(void ){
	fill (p, p+MAX_N, true );
	p[0] = false;
	p[1] = false;
	
	for (int i = 2; i <= MAX_N; i++ ){
		if (p[i] ){
			for (int j = 2*i; j <= MAX_N; j += i ){
				p[j] = false;
			} // end for
		} // end if
	} // end for

	prime.clear();
	for (int i = 2; i <= MAX_N; i++ ){
		if (p[i] ) prime.push_back (i );
	} // end for
}

int cnt[10];

int main()
{
	sieve ();
	memset (cnt, 0, sizeof (cnt ) );
	ios_base::sync_with_stdio(0);

	int mask = 0;
	int N; cin >> N;
	rep (i, N ){
		int in; cin >> in;
		mask |= 1<<in;
	} // end rep

	int curr = 0;
	int res = -1;
	int l = 1, r = 1;
	int k = 0;
	while (r <= MAX_N ){
		if (curr == mask ) res = max (res, r - l - 1 );
		if (curr <= mask ){
			k = r++; if (!p[k] ) k = 0;
			while (k > 0 ){
				cnt[k % 10 ]++;
				if (cnt[k % 10 ] == 1 ) curr ^= (1 << (k % 10 ) );
				k /= 10;
			} // end while
		} // end if

		if (curr == mask ) res = max (res, r - l - 1 );
		if (curr > mask ){
			k = l++; if (!p[k] ) k = 0;
			while (k > 0 ){
				cnt[k % 10 ]--;
				if (!cnt[k % 10 ] ) curr ^= (1 << (k % 10 ) );
				k /= 10;
			} // end while
		} // end if	 
	} // end while

	cout << res << endl;
	
	return 0;
}