#include <iostream>

int main() {
    int n;
    std::cin >> n;
    n--;
    int c = n / 36;
    int p = n % 36;
    int a = -1, b = -1;
    for (int i = 1; i <= 9; i++) {
        for (int j = i + 1; j <= 9; j++) {
            if (p == 0) {
                a = i;
                b = j;
            }
            p--;
        }
    }
    std::cout << a << b;
    while (c--) {
        std::cout << b;
    }
    std::cout << '\n';
}