【題目敘述】https://atcoder.jp/contests/abc161/tasks/abc161_d
#include <iostream>
#include <queue>
using namespace std;
long long k, ans[100005], idx = 1;
queue <long long> q;
int main(){
cin >> k;
for (int i = 1; i < 10; i++){
q.push(i);
}
while (ans[k] == 0){
long long now = q.front();
q.pop();
int n = now % 10;
if (n != 0) q.push(now * 10 + n - 1);
q.push(now * 10 + n);
if (n != 9) q.push(now * 10 + n + 1);
ans[idx] = now;
idx++;
}
cout << ans[k] << "\n";
}