#include <iostream>
#include <vector>
using namespace std;
int n;


int main()
{
    int n;
    cin >> n;
    string s;
    cin >> s;
    int combs = 0;
    for(int mask = 0; mask < (1 << n); mask++) {
        string tmp = "";
        for(int i = 0; i < n; i++) {
            if(mask & (1 << i)) {
                tmp += s[i];
            }
        }
        string ltd = "";
        if(tmp.size() == 1) {
            ltd += tmp[tmp.size() - 1];
        }
        else if(tmp.size() == 2) {
            ltd += tmp[tmp.size() - 2];
            ltd += tmp[tmp.size() - 1];
        }
        else {
            ltd += tmp[tmp.size() - 3];
            ltd += tmp[tmp.size() - 2];
            ltd += tmp[tmp.size() - 1];
        }
        int num = 0;
        for(int j = 0; j < ltd.size(); j++) {
            num = (num * 10) + (ltd[j] - '0');
        }
        if(num % 8 == 0) {
            ++combs;
        }
    }
    cout << combs - 1<< endl;
    return 0;
}