#include <bits/stdc++.h>
using namespace std;
int main()
{
int k, a;
string s;
cin >> k;
for(int i = 0 ; i < k ; i++) cin >> a;
stringstream ans;
ans << k;
ans >> s;
if(k == 1 and a != 0) cout << a << endl;
else if(a == 0)
{
if(k == 1) cout << 10 << endl;
else cout << pow(10, s.size()+1) << endl;
}
else if(a == 9)
{
int t = pow(10, s.size()-2);
if(t == 1) t = 0;
if(s.size() == 1) cout << 89 << endl;
else if(t+1 + pow(10, s.size()-1) > k) cout << pow(10, s.size()-1)*9 - t-1 << endl;
else cout << pow(10, s.size())*9 - pow(10, s.size()-1)-1 << endl;
}
else cout << pow(10, s.size())*a << endl;
}
