Language: C++

#include <bits/stdc++.h>
//#pragma GCC optimize ("O3")

#define yu using
#define don namespace
#define sei std

yu don sei;

vector<ll>A = {1,2,3,4,5,6,7,8,9,19,29,39,49,59,69,79,89,99,199,299,399,499,599,699,799,899,999,1099,1199,1299,1399,1499,1599,1699,1799,1899,1999,2999,3999,4999,5999,6999,7999,8999,9999,10999,11999,12999,13999,14999,15999,16999,17999,18999,19999,20999,21999,22999,23999,24999,25999,26999,27999,28999,29999,39999,49999,59999,69999,79999,89999,99999,109999,119999,129999,139999,149999,159999,169999,179999,189999,199999,209999,219999,229999,239999,249999,259999,269999,279999,289999,299999,309999,319999,329999,339999,349999,359999,369999,379999,389999,399999,499999,599999,699999,799999,899999,999999,1099999,1199999,1299999,1399999,1499999,1599999,1699999,1799999,1899999,1999999,2099999,2199999,2299999,2399999,2499999,2599999,2699999,2799999,2899999,2999999,3099999,3199999,3299999,3399999,3499999,3599999,3699999,3799999,3899999,3999999,4099999,4199999,4299999,4399999,4499999,4599999,4699999,4799999,4899999,4999999,5999999,6999999,7999999,8999999,9999999,9999999,10999999,11999999,12999999,13999999,14999999,15999999,16999999,17999999,18999999,19999999,20999999,21999999,22999999,23999999,24999999,25999999,26999999,27999999,28999999,29999999,30999999,31999999,32999999,33999999,34999999,35999999,36999999,37999999,38999999,39999999,40999999,41999999,42999999,43999999,44999999,45999999,46999999,47999999,48999999,49999999,50999999,51999999,52999999,53999999,54999999,55999999,56999999,57999999,58999999,59999999,69999999,79999999,89999999,99999999,109999999,119999999,129999999,139999999,149999999,159999999,169999999,179999999,189999999,199999999,209999999,219999999,229999999,239999999,249999999,259999999,269999999,279999999,289999999,299999999,309999999,319999999,329999999,339999999,349999999,359999999,369999999,379999999,389999999,399999999,409999999,419999999,429999999,439999999,449999999,459999999,469999999,479999999,489999999,499999999,509999999,519999999,529999999,539999999,549999999,559999999,569999999,579999999,589999999,599999999,609999999,619999999,629999999,639999999,649999999,659999999,669999999,679999999,689999999,699999999,799999999,899999999,999999999,1099999999,1199999999,1299999999,1399999999,1499999999,1599999999,1699999999,1799999999,1899999999,1999999999,2099999999,2199999999,2299999999,2399999999,2499999999,2599999999,2699999999,2799999999,2899999999,2999999999,3099999999,3199999999,3299999999,3399999999,3499999999,3599999999,3699999999,3799999999,3899999999,3999999999,4099999999,4199999999,4299999999,4399999999,4499999999,4599999999,4699999999,4799999999,4899999999,4999999999,5099999999,5199999999,5299999999,5399999999,5499999999,5599999999,5699999999,5799999999,5899999999,5999999999,6099999999,6199999999,6299999999,6399999999,6499999999,6599999999,6699999999,6799999999,6899999999,6999999999,7099999999,7199999999,7299999999,7399999999,7499999999,7599999999,7699999999,7799999999,7899999999,7999999999,8999999999,9999999999,9999999999,10999999999,11999999999,12999999999,13999999999,14999999999,15999999999,16999999999,17999999999,18999999999,19999999999,20999999999,21999999999,22999999999,23999999999,24999999999,25999999999,26999999999,27999999999,28999999999,29999999999,30999999999,31999999999,32999999999,33999999999,34999999999,35999999999,36999999999,37999999999,38999999999,39999999999,40999999999,41999999999,42999999999,43999999999,44999999999,45999999999,46999999999,47999999999,48999999999,49999999999,50999999999,51999999999,52999999999,53999999999,54999999999,55999999999,56999999999,57999999999,58999999999,59999999999,60999999999,61999999999,62999999999,63999999999,64999999999,65999999999,66999999999,67999999999,68999999999,69999999999,70999999999,71999999999,72999999999,73999999999,74999999999,75999999999,76999999999,77999999999,78999999999,79999999999,80999999999,81999999999,82999999999,83999999999,84999999999,85999999999,86999999999,87999999999,88999999999,89999999999,99999999999,109999999999,119999999999,129999999999,139999999999,149999999999,159999999999,169999999999,179999999999,189999999999,199999999999,209999999999,219999999999,229999999999,239999999999,249999999999,259999999999,269999999999,279999999999,289999999999,299999999999,309999999999,319999999999,329999999999,339999999999,349999999999,359999999999,369999999999,379999999999,389999999999,399999999999,409999999999,419999999999,429999999999,439999999999,449999999999,459999999999,469999999999,479999999999,489999999999,499999999999,509999999999,519999999999,529999999999,539999999999,549999999999,559999999999,569999999999,579999999999,589999999999,599999999999,609999999999,619999999999,629999999999,639999999999,649999999999,659999999999,669999999999,679999999999,689999999999,699999999999,709999999999,719999999999,729999999999,739999999999,749999999999,759999999999,769999999999,779999999999,789999999999,799999999999,809999999999,819999999999,829999999999,839999999999,849999999999,859999999999,869999999999,879999999999,889999999999,899999999999,909999999999,919999999999,929999999999,939999999999,949999999999,959999999999,969999999999,979999999999,989999999999,999999999999,1099999999999,1199999999999,1299999999999,1399999999999,1499999999999,1599999999999,1699999999999,1799999999999,1899999999999,1999999999999,2099999999999,2199999999999,2299999999999,2399999999999,2499999999999,2599999999999,2699999999999,2799999999999,2899999999999,2999999999999,3099999999999,3199999999999,3299999999999,3399999999999,3499999999999,3599999999999,3699999999999,3799999999999,3899999999999,3999999999999,4099999999999,4199999999999,4299999999999,4399999999999,4499999999999,4599999999999,4699999999999,4799999999999,4899999999999,4999999999999,5099999999999,5199999999999,5299999999999,5399999999999,5499999999999,5599999999999,5699999999999,5799999999999,5899999999999,5999999999999,6099999999999,6199999999999,6299999999999,6399999999999,6499999999999,6599999999999,6699999999999,6799999999999,6899999999999,6999999999999,7099999999999,7199999999999,7299999999999,7399999999999,7499999999999,7599999999999,7699999999999,7799999999999,7899999999999,7999999999999,8099999999999,8199999999999,8299999999999,8399999999999,8499999999999,8599999999999,8699999999999,8799999999999,8899999999999,8999999999999,9099999999999,9199999999999,9299999999999,9399999999999,9499999999999,9599999999999,9699999999999,9799999999999,9899999999999,9999999999999,10999999999999,11999999999999,12999999999999,13999999999999,14999999999999,15999999999999,16999999999999,17999999999999,18999999999999,19999999999999,20999999999999,21999999999999,22999999999999,23999999999999,24999999999999,25999999999999,26999999999999,27999999999999,28999999999999,29999999999999,30999999999999,31999999999999,32999999999999,33999999999999,34999999999999,35999999999999,36999999999999,37999999999999,38999999999999,39999999999999,40999999999999,41999999999999,42999999999999,43999999999999,44999999999999,45999999999999,46999999999999,47999999999999,48999999999999,49999999999999,50999999999999,51999999999999,52999999999999,53999999999999,54999999999999,55999999999999,56999999999999,57999999999999,58999999999999,59999999999999,60999999999999,61999999999999,62999999999999,63999999999999,64999999999999,65999999999999,66999999999999,67999999999999,68999999999999,69999999999999,70999999999999,71999999999999,72999999999999,73999999999999,74999999999999,75999999999999,76999999999999,77999999999999,78999999999999,79999999999999,80999999999999,81999999999999,82999999999999,83999999999999,84999999999999,85999999999999,86999999999999,87999999999999,88999999999999,89999999999999,90999999999999,91999999999999,92999999999999,93999999999999,94999999999999,95999999999999,96999999999999,97999999999999,98999999999999,99999999999999,100999999999999,101999999999999,102999999999999,103999999999999,104999999999999,105999999999999,106999999999999,107999999999999,108999999999999,109999999999999,119999999999999,129999999999999,139999999999999,149999999999999,159999999999999,169999999999999,179999999999999,189999999999999,199999999999999,209999999999999,219999999999999,229999999999999,239999999999999,249999999999999,259999999999999,269999999999999,279999999999999,289999999999999,299999999999999,309999999999999,319999999999999,329999999999999,339999999999999,349999999999999,359999999999999,369999999999999,379999999999999,389999999999999,399999999999999,409999999999999,419999999999999,429999999999999,439999999999999,449999999999999,459999999999999,469999999999999,479999999999999,489999999999999,499999999999999,509999999999999,519999999999999,529999999999999,539999999999999,549999999999999,559999999999999,569999999999999,579999999999999,589999999999999,599999999999999,609999999999999,619999999999999,629999999999999,639999999999999,649999999999999,659999999999999,669999999999999,679999999999999,689999999999999,699999999999999,709999999999999,719999999999999,729999999999999,739999999999999,749999999999999,759999999999999,769999999999999,779999999999999,789999999999999,799999999999999,809999999999999,819999999999999,829999999999999,839999999999999,849999999999999,859999999999999,869999999999999,879999999999999,889999999999999,899999999999999,909999999999999,919999999999999,929999999999999,939999999999999,949999999999999,959999999999999,969999999999999,979999999999999,989999999999999,999999999999999};
int main()
{

	int k;
	cin>>k;
	k--;
	cout<<A[k]<<endl;
	return 0;
}

Compiler output:
a.cc:10:8: error: 'll' was not declared in this scope
   10 | vector<ll>A = {1,2,3,4,5,6,7,8,9,19,29,39,49,59,69,79,89,99,199,299,399,499,599,699,799,899,999,1099,1199,1299,1399,1499,1599,1699,1799,1899,1999,2999,3999,4999,5999,6999,7999,8999,9999,10999,11999,12999,13999,14999,15999,16999,17999,18999,19999,20999,21999,22999,23999,24999,25999,26999,27999,28999,29999,39999,49999,59999,69999,79999,89999,99999,109999,119999,129999,139999,149999,159999,169999,179999,189999,199999,209999,219999,229999,239999,249999,259999,269999,279999,289999,299999,309999,319999,329999,339999,349999,359999,369999,379999,389999,399999,499999,599999,699999,799999,899999,999999,1099999,1199999,1299999,1399999,1499999,1599999,1699999,1799999,1899999,1999999,2099999,2199999,2299999,2399999,2499999,2599999,2699999,2799999,2899999,2999999,3099999,3199999,3299999,3399999,3499999,3599999,3699999,3799999,3899999,3999999,4099999,4199999,4299999,4399999,4499999,4599999,4699999,4799999,4899999,4999999,5999999,6999999,7999999,8999999,9999999,9999999,10999999,11999999,12999999,13999999,14999999,15999999,16999999,17999999,18999999,19999999,20999999,21999999,22999999,23999999,24999999,25999999,26999999,27999999,28999999,29999999,30999999,31999999,32999999,33999999,34999999,35999999,36999999,37999999,38999999,39999999,40999999,41999999,42999999,43999999,44999999,45999999,46999999,47999999,48999999,49999999,50999999,51999999,52999999,53999999,54999999,55999999,56999999,57999999,58999999,59999999,69999999,79999999,89999999,99999999,109999999,119999999,129999999,139999999,149999999,159999999,169999999,179999999,189999999,199999999,209999999,219999999,229999999,239999999,249999999,259999999,269999999,279999999,289999999,299999999,309999999,319999999,329999999,339999999,349999999,359999999,369999999,379999999,389999999,399999999,409999999,419999999,429999999,439999999,449999999,459999999,469999999,479999999,489999999,499999999,509999999,519999999,529999999,539999999,549999999,559999999,569999999,579999999,589999999,599999999,609999999,619999999,629999999,639999999,649999999,659999999,669999999,679999999,689999999,699999999,799999999,899999999,999999999,1099999999,1199999999,1299999999,1399999999,1499999999,1599999999,1699999999,1799999999,1899999999,1999999999,2099999999,2199999999,2299999999,2399999999,2499999999,2599999999,2699999999,2799999999,2899999999,2999999999,3099999999,3199999999,3299999999,3399999999,3499999999,3599999999,3699999999,3799999999,3899999999,3999999999,4099999999,4199999999,4299999999,4399999999,4499999999,4599999999,4699999999,4799999999,4899999999,4999999999,5099999999,5199999999,5299999999,5399999999,5499999999,5599999999,5699999999,5799999999,5899999999,5999999999,6099999999,6199999999,6299999999,6399999999,6499999999,6599999999,6699999999,6799999999,6899999999,6999999999,7099999999,7199999999,7299999999,7399999999,7499999999,7599999999,7699999999,7799999999,7899999999,7999999999,8999999999,9999999999,9999999999,10999999999,11999999999,12999999999,13999999999,14999999999,15999999999,16999999999,17999999999,18999999999,19999999999,20999999999,21999999999,22999999999,23999999999,24999999999,25999999999,26999999999,27999999999,28999999999,29999999999,30999999999,31999999999,32999999999,33999999999,34999999999,35999999999,36999999999,37999999999,38999999999,39999999999,40999999999,41999999999,42999999999,43999999999,44999999999,45999999999,46999999999,47999999999,48999999999,49999999999,50999999999,51999999999,52999999999,53999999999,54999999999,55999999999,56999999999,57999999999,58999999999,59999999999,60999999999,61999999999,62999999999,63999999999,64999999999,65999999999,66999999999,67999999999,68999999999,69999999999,70999999999,71999999999,72999999999,73999999999,74999999999,75999999999,76999999999,77999999999,78999999999,79999999999,80999999999,81999999999,82999999999,83999999999,84999999999,85999999999,86999999999,87999999999,88999999999,89999999999,99999999999,109999999999,119999999999,129999999999,139999999999,149999999999,159999999999,169999999999,179999999999,189999999999,199999999999,209999999999,219999999999,229999999999,239999999999,249999999999,259999999999,269999999999,279999999999,289999999999,299999999999,309999999999,319999999999,329999999999,339999999999,349999999999,359999999999,369999999999,379999999999,389999999999,399999999999,409999999999,419999999999,429999999999,439999999999,449999999999,459999999999,469999999999,479999999999,489999999999,499999999999,509999999999,519999999999,529999999999,539999999999,549999999999,559999999999,569999999999,579999999999,589999999999,599999999999,609999999999,619999999999,629999999999,639999999999,649999999999,659999999999,669999999999,679999999999,689999999999,699999999999,709999999999,719999999999,729999999999,739999999999,749999999999,759999999999,769999999999,779999999999,789999999999,799999999999,809999999999,819999999999,829999999999,839999999999,849999999999,859999999999,869999999999,879999999999,889999999999,899999999999,909999999999,919999999999,929999999999,939999999999,949999999999,959999999999,969999999999,979999999999,989999999999,999999999999,1099999999999,1199999999999,1299999999999,1399999999999,1499999999999,1599999999999,1699999999999,1799999999999,1899999999999,1999999999999,2099999999999,2199999999999,2299999999999,2399999999999,2499999999999,2599999999999,2699999999999,2799999999999,2899999999999,2999999999999,3099999999999,3199999999999,3299999999999,3399999999999,3499999999999,3599999999999,3699999999999,3799999999999,3899999999999,3999999999999,4099999999999,4199999999999,4299999999999,4399999999999,4499999999999,4599999999999,4699999999999,4799999999999,4899999999999,4999999999999,5099999999999,5199999999999,5299999999999,5399999999999,5499999999999,5599999999999,5699999999999,5799999999999,5899999999999,5999999999999,6099999999999,6199999999999,6299999999999,6399999999999,6499999999999,6599999999999,6699999999999,6799999999999,6899999999999,6999999999999,7099999999999,7199999999999,7299999999999,7399999999999,7499999999999,7599999999999,7699999999999,7799999999999,7899999999999,7999999999999,8099999999999,8199999999999,8299999999999,8399999999999,8499999999999,8599999999999,8699999999999,8799999999999,8899999999999,8999999999999,9099999999999,9199999999999,9299999999999,9399999999999,9499999999999,9599999999999,9699999999999,9799999999999,9899999999999,9999999999999,10999999999999,11999999999999,12999999999999,13999999999999,14999999999999,15999999999999,16999999999999,17999999999999,18999999999999,19999999999999,20999999999999,21999999999999,22999999999999,23999999999999,24999999999999,25999999999999,26999999999999,27999999999999,28999999999999,29999999999999,30999999999999,31999999999999,32999999999999,33999999999999,34999999999999,35999999999999,36999999999999,37999999999999,38999999999999,39999999999999,40999999999999,41999999999999,42999999999999,43999999999999,44999999999999,45999999999999,46999999999999,47999999999999,48999999999999,49999999999999,50999999999999,51999999999999,52999999999999,53999999999999,54999999999999,55999999999999,56999999999999,57999999999999,58999999999999,59999999999999,60999999999999,61999999999999,62999999999999,63999999999999,64999999999999,65999999999999,66999999999999,67999999999999,68999999999999,69999999999999,70999999999999,71999999999999,72999999999999,73999999999999,74999999999999,75999999999999,76999999999999,77999999999999,78999999999999,79999999999999,80999999999999,81999999999999,82999999999999,83999999999999,84999999999999,85999999999999,86999999999999,87999999999999,88999999999999,89999999999999,90999999999999,91999999999999,92999999999999,93999999999999,94999999999999,95999999999999,96999999999999,97999999999999,98999999999999,99999999999999,100999999999999,101999999999999,102999999999999,103999999999999,104999999999999,105999999999999,106999999999999,107999999999999,108999999999999,109999999999999,119999999999999,129999999999999,139999999999999,149999999999999,159999999999999,169999999999999,179999999999999,189999999999999,199999999999999,209999999999999,219999999999999,229999999999999,239999999999999,249999999999999,259999999999999,269999999999999,279999999999999,289999999999999,299999999999999,309999999999999,319999999999999,329999999999999,339999999999999,349999999999999,359999999999999,369999999999999,379999999999999,389999999999999,399999999999999,409999999999999,419999999999999,429999999999999,439999999999999,449999999999999,459999999999999,469999999999999,479999999999999,489999999999999,499999999999999,509999999999999,519999999999999,529999999999999,539999999999999,549999999999999,559999999999999,569999999999999,579999999999999,589999999999999,599999999999999,609999999999999,619999999999999,629999999999999,639999999999999,649999999999999,659999999999999,669999999999999,679999999999999,689999999999999,699999999999999,709999999999999,719999999999999,729999999999999,739999999999999,749999999999999,759999999999999,769999999999999,779999999999999,789999999999999,799999999999999,809999999999999,819999999999999,829999999999999,839999999999999,849999999999999,859999999999999,869999999999999,879999999999999,889999999999999,899999999999999,909999999999999,919999999999999,929999999999999,939999999999999,949999999999999,959999999999999,969999999999999,979999999999999,989999999999999,999999999999999};
      |        ^~
a.cc:10:10: error: template argument 1 is invalid
   10 | vector<ll>A = {1,2,3,4,5,6,7,8,9,19,29,39,49,59,69,79,89,99,199,299,399,499,599,699,799,899,999,1099,1199,1299,1399,1499,1599,1699,1799,1899,1999,2999,3999,4999,5999,6999,7999,8999,9999,10999,11999,12999,13999,14999,15999,16999,17999,18999,19999,20999,21999,22999,23999,24999,25999,26999,27999,28999,29999,39999,49999,59999,69999,79999,89999,99999,109999,119999,129999,139999,149999,159999,169999,179999,189999,199999,209999,219999,229999,239999,249999,259999,269999,279999,289999,299999,309999,319999,329999,339999,349999,359999,369999,379999,389999,399999,499999,599999,699999,799999,899999,999999,1099999,1199999,1299999,1399999,1499999,1599999,1699999,1799999,1899999,1999999,2099999,2199999,2299999,2399999,2499999,2599999,2699999,2799999,2899999,2999999,3099999,3199999,3299999,3399999,3499999,3599999,3699999,3799999,3899999,3999999,4099999,4199999,4299999,4399999,449999