#include <iostream>

int main() {
    int N;
    std::cin >> N;
    int count = 0;
    for (int i = 8; i <= N; i++) {
        if (i % 10 == 8 || i / 10 % 10 == 8 || i / 100 == 8) count++;
    }
    std::cout << count << std::endl;
}