B. Perfect Number
time limit per test2 seconds
memory limit per test256 megabytes
inputstandard input
outputstandard output
We consider a positive integer perfect, if and only if the sum of its digits is exactly 10. Given a positive integer k, your task is to find the k-th smallest perfect positive integer.

Input
A single line with a positive integer k (1 ≤ k ≤ 10 000).

Output
A single number, denoting the k-th smallest perfect integer.

Examples
input
1
output
19
input
2
output
28

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
typedef long long
 
 ll;
int main()
{
    int k;
    scanf("%d",&k);
    int cnt = 0;
    ll x;
    for(ll a = 19;; a ++)
    {
        x = a;
        int sum = 0;
        while(x)
        {
            sum=sum+x%10;
            x/=10;
        }
        if(sum==10)
            cnt++;
        if(cnt==k)
        {
            printf
 
("%lld",a);
            return 0;
        }
    }
    return 0;
}