#include <iostream>
using namespace std;
const int MAX = 1e5 + 69;
int n;
int ar[MAX];
int val0[6] = {1, 10, 100, 1000, 10000, 100000};
int val1[6] = {1, 11, 111, 1111, 11111, 111111};
inline bool yes(int num)
{
for (int i = 0; i < n; ++i)
{
bool ok = false;
int tmp = num + i;
while (tmp)
{
if (tmp % 10 == ar[i]) { ok = true; break; }
tmp /= 10;
}
if (!ok)
return false;
}
return true;
}
inline int brute()
{
for (int i = 1;; ++i)
{
if (yes(i))
return i;
}
return -1;
}
inline int greedy()
{
if (ar[0] == 0)
{
int id = -1;
for (int i = 0; i < 6; ++i)
{
if (val1[i] >= n)
{
id = i;
break;
}
}
int res = 10;
for (int i = 0; i < id; ++i)
res *= 10;
return res;
}
else if (ar[0] <= 8)
{
int id = -1;
for (int i = 0; i < 6; ++i)
{
if (val0[i] >= n)
{
id = i;
break;
}
}
int res = ar[0];
for (int i = 0; i < id; ++i)
res *= 10;
return res;
}
else
{
int id = -1;
for (int i = 0; i < 6; ++i)
{
if (val1[i] >= n)
{
id = i;
break;
}
}
int res = 0;
for (int i = 0; i < id; ++i)
res = res * 10 + 8;
return res * 10 + 9;
}
}
int main()
{
ios :: sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> n;
for (int i = 0; i < n; ++i)
cin >> ar[i];
cout << greedy() << '\n';;
return 0;
}
