#define pragma

#ifdef pragma
#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#endif // pragma

#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define ll long long
#define all(x) begin(x), end(x)
#define pb push_back
#define x first
#define y second
//#define int long long
#define zero(two) memset(two, 0, sizeof(two))

using namespace std;
using namespace __gnu_pbds;


typedef vector<int> vi;
typedef vector<bool> vb;
typedef pair<int, int> pii;
typedef long double ld;
typedef vector<vi> matrix;
template<typename T>
using kawaii_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

const ld PI = atan2(0, -1);

void seriy() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
//    cout << fixed << setprecision(10);
    #if _offline
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
    #endif
}

const int MAXN = 1e6 + 10;
const int INF = 1e9 + 7;
const int MAXLOG = 20;
const int MOD = 998244353;
const int BASE = 47;

vi mn(vi a, vi b) {
    vi c = a;
    vi d = b;
    while(a.size() && a.back() == b.back()) {
        a.pop_back();
        b.pop_back();
    }
    if(!a.size()) return c;
    if(a.back() < b.back()) {
        return c;
    }
    return d;
}

signed main() {
    seriy();
    int n;
    cin >> n;
    vector<string> s(n);
    vi a(n);
    vi cnt(MAXN);
    bool f = 0;
    vector<vi> r(n);
    vi lst(n);
    for(int i = 0; i < n; i++) {
        cin >> s[i];
        reverse(all(s[i]));
        int cc = 0;
        for(int j = 0; j < s[i].size(); j++) {
            r[i].pb(s[i][j] - '0');
            if(s[i][j] == '1') {
                cc++;
                lst[i] = j;
                a[i] = j;
            }
        }
        f = f | (cc > 1);
        cnt[a[i]]++;
    }
    if(!f) {
        vb used(MAXN);
        for(int i = 0; i < MAXN; i++) {
            if(cnt[i] > 0) {
                used[i] = 1;
                cnt[i + 1] += cnt[i] - 1;
            }
        }
        while(used.back() == 0) {
            used.pop_back();
        }
        reverse(all(used));
        for(auto i : used) {
            cout << i;
        }
        return 0;
    }
    while(r[0].size() < r[1].size()) {
        r[0].pb(0);
    }
    while(r[1].size() < r[0].size()) {
        r[1].pb(0);
    }
    r[0].pb(0);
    r[0].pb(0);
    r[1].pb(0);
    r[1].pb(0);
    vi ans(r[0].size(), 1);

    for(int i = 0; i < r[0].size(); i++) {
        vector<vi> b = r;
        for(int j = 0; j < i; j++) {
            b[0][j] = 0;
        }
        if(i > lst[0] || b[0][i] == 0) {
            b[0][i] = 1;
        }
        else {
            continue;
        }
//        for(auto j : b[0]) {
//            cerr << j;
//        }
//        cerr << '\n';
//        for(auto j : b[1]) {
//            cerr << j;
//        }
//        cerr << '\n' << '\n';
        vi kek(r[0].size());
        bool f = 0;
        for(int j = 0; j < b[0].size(); j++) {
            f = f | (b[0][j] & b[1][j]);
            kek[j] = b[0][j] | b[1][j];
        }
        if(!f) {
            ans = mn(ans, kek);
        }
    }

    for(int i = 0; i < r[1].size(); i++) {
        vector<vi> b = r;
        for(int j = 0; j < i; j++) {
            b[1][j] = 0;
        }
        if(i > lst[1] || b[1][i] == 0) {
            b[1][i] = 1;
        }
        else {
            continue;
        }
        bool f = 0;
        vi kek(r[0].size());
        for(int j = 0; j < b[1].size(); j++) {
            f = f | (b[0][j] & b[1][j]);
            kek[j] = b[0][j] | b[1][j];
        }
        if(!f) {
            ans = mn(ans, kek);
        }
    }
    vi kek(r[0].size());
    bool fl = 0;
    for(int j = 0; j < r[1].size(); j++) {
        kek[j] = r[0][j] | r[1][j];
        fl = fl | (r[0][j] & r[1][j]);
    }
    if(!fl) {
        ans = mn(ans, kek);
    }
    while(ans.back() == 0) {
        ans.pop_back();
    }
    while(ans.size()) {
        cout << ans.back();
        ans.pop_back();
    }
    return 0;

}