#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
bool getbit(int mask, int bit) {
return mask & (1 << bit);
}
const int N = 1e6 + 10;
const int K = 1e5 + 10;
int b[K];
int mask[N];
void init() {
mask[0] = (1 << 0);
for (int i = 1; i <= N - 1; i++) {
for (int j = i; j >= 1; j /= 10) {
mask[i] |= (1 << (j % 10));
}
}
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
#ifdef LOCAL
freopen("input.txt", "r", stdin);
#endif
init();
int k;
cin >> k;
for (int i = 1; i <= k; i++) {
cin >> b[i];
}
if (k >= 1000 + 1) {
cout << "1\n";
return 0;
}
int ans = -1;
for (int n = 1; n + k - 1 <= N - 1; n++) {
bool ok = true;
for (int i = 1; i <= k; i++) {
ok &= getbit(mask[n + i - 1], b[i]);
}
if (ok) {
ans = n;
break;
}
}
cout << ans << "\n";
#ifdef LOCAL
cout << "\nTime elapsed: " << double(clock()) / CLOCKS_PER_SEC << " s.\n";
#endif
}
