#include <bits/stdc++.h>
using namespace std;
int n;
vector <int> a, b(105, 0), v;
bool f(int x){
for(int i = 1; i <= n; i++){
int x1 = x;
bool tr = 0;
while(x1){
if(x1 % 10 == a[i]){
tr = 1;
break;
}
x1 /= 10;
}
if(tr == 0) return false;
x++;
}
return true;
}
int main(){
ios::sync_with_stdio(false); cin.tie(nullptr);
cin >> n;
a.resize(n);
int mx = 0, mn = 1e9;
for(int i = 0; i < n; i++){
cin >> a[i];
mn = min(mn, a[i]), mx = max(mx, a[i]);
}
if(mx != mn){
for(int i = 1; i <= 20000; i++){
if(f(i)){
cout << i;
return 0;
}
}
}
if(a[0] == 0 or a[0] == 9){
int x = 1, k1 = 10, k2 = 8;
while(x < n){
k1 *= 10;
k2 *= 10;
k2 += 8;
x *= 10;
x++;
}
if(a[0] == 0) cout << k1;
else cout << k2+1;
return 0;
}
int x = 1;
while(x < n){
x *= 10;
}
x *= a[0];
cout << x;
return 0;
}
