N1

#include <iostream>
#include <cmath>
#include <vector>
#include <queue>
#include <algorithm>
#include <string>
#include <stack>
#include <set>
#include <map>
#define pii pair <int, int>
#define pb(x) push_back(x)
using namespace std;
using ll = long long;
using ld = long double;
using db = double;
void cv(vector <int> &v) {
    for (auto x : v) cout << x << ' ';
    cout << "\n";
}

void cvl(vector <ll> &v) {
    for (auto x : v) cout << x << ' ';
    cout << "\n";
}


void cvv(vector <vector <int> > &v) {
    for (auto x : v) cv(x);
    cout << "\n";
}

void cvb(vector <bool> v) {
    for (bool x : v) cout << x << ' ';
    cout << "\n";
}

void cvs(vector <string>  v) {
    for (auto a : v) {
        cout << a << "\n";
    }
}

void cvp(vector <pii> a) {
    for (auto p : a) {
        cout << p.first << ' ' << p.second << "\n";
    }
    cout << "\n";
}



int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    string s;
    cin >> s;
    //reverse(s.begin(), s.end());
    bool sh = 0;
    int n = s.size();
    int id = 0, cnt = 0;
    for (int i = n - 4; i >= 0; --i) {
        cnt++;
        string a = s.substr(i, 2), b = s.substr(i + 2, 2);
        int x = stoi(a), y = stoi(b);
        if (sh) {
            cout << i << ' ' << a << ' ' << b << "\n";
            cout << x << ' ' << y << "\n";
            cout << x % 8 << ' ' << y % 8 << "\n";
        }
        if (x % 8 == y % 8) {
            id = cnt;
            break;
        }
    }
    cout << id;
}