/// ITNOG
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>
using namespace std;
constexpr int MOD = 1e9 + 7, N = 1e7 + 8, M = 1e6, SQ = 600, INF = 1e9 + 8, LGN = 22, mod = 998244353, P = 131113;
bool mark[N][10];
int n, a[N];
int32_t main(){
ios::sync_with_stdio(false);
cin.tie(NULL);
for (int i = 0; i < N; ++ i){
string s = to_string(i);
for (char ch : s){
mark[i][ch-'0'] = true;
}
}
cin >> n;
for (int i = 0; i < N; ++ i){
cin >> a[i];
}
for (int i = 1; i < N; ++ i){
bool ok = true;
for (int j = 0; j < n; ++ j){
if (!mark[i+j][a[j]]){
ok = false;
}
}
if (ok){
cout << i;
return 0;
}
}
cout << -1;
return 0;
}
// Yesterday is history
// Tomorrow is a mystery
// but today is a gift
// That is why it is called the present
