#include "bits/stdc++.h"
using namespace std;
#define ll long long int
#define rep(i,n) for( int i = 0; i < n; i++ )
#define rrep(i,n) for( int i = n; i >= 0; i-- )
#define REP(i,s,t) for( int i = s; i <= t; i++ )
#define RREP(i,s,t) for( int i = s; i >= t; i-- )
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define INF 2000000000
#define mod 1000000007
#define INF2 5000000000000000000
#define int long long

int calc1(int base, string num) {
	int ret = 0;
	int times = 1;
	RREP(i, num.length() - 1, 0) {
		if (num[i] <= '9') ret += (num[i] - '0') * times;
		else ret += (num[i] - 'A' + 10) * times;
		times *= base;
	}
	return ret;
}

signed main(void)
{
    cin.tie(0);
    ios::sync_with_stdio(false);
	int N; cin >> N;
	string S[1010];
	rep(i, N) cin >> S[i];
	int ans = INF2;
	rep(i, N) {
		char maxc = '0';
		rep(j, S[i].length()) {
			maxc = max(maxc, S[i][j]);
		}	
		int minx = 2;
		if (maxc <= '9') {
			minx = max(minx, (int)maxc - '0' + 1);
		}
		else {
			minx = maxc - 'A' + 11;
		}
		//cout << minx << endl;
		REP(j, minx, 36) {
			ans = min(ans, calc1(j, S[i]));
		}
	}

	cout << ans << endl;


    return 0;
}