/*
    Author:zeke
    
    pass System Test!
    GET AC!!
*/
#include <iostream>
#include <queue>
#include <vector>
#include <iostream>
#include <vector>
#include <string>
#include <cassert>
#include <algorithm>
#include <functional>
#include <cmath>
#include <queue>
#include <set>
#include <stack>
#include <deque>
#include <map>
#include <iomanip>
#include <utility>
#include <stack>
using ll = long long;
using ld = long double;
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define all(x) (x).begin(), (x).end()
#define rep3(var, min, max) for (ll(var) = (min); (var) < (max); ++(var))
#define repi3(var, min, max) for (ll(var) = (max)-1; (var) + 1 > (min); --(var))
#define Mp(a, b) make_pair((a), (b))
#define F first
#define S second
#define Icin(s) \
    ll(s);      \
    cin >> (s);
#define Scin(s) \
    ll(s);      \
    cin >> (s);
template <class T>
bool chmax(T &a, const T &b)
{
    if (a < b)
    {
        a = b;
        return 1;
    }
    return 0;
}
template <class T>
bool chmin(T &a, const T &b)
{
    if (b < a)
    {
        a = b;
        return 1;
    }
    return 0;
}
typedef pair<ll, ll> P;
typedef vector<ll> V;
typedef vector<V> VV;
typedef vector<P> VP;
ll MOD = 1e9 + 7;
ll INF = 1e18;
ll a, b, p, q, r;
ll judge(ld x)
{
    ld res = (x - a) * q;
    res += (x - b) * r;
    ld temp = p * b;
    return temp <= res;
}
struct fenwick_tree
{
    typedef int T;
    T n;
    vector<T> bit;

    // 各要素の初期値は 0
    fenwick_tree(T num) : bit(num + 1, 0) { n = num; }

    // a_i += w
    void add(T i, T w)
    {
        for (T x = i; x <= n; x += x & -x)
        {
            bit[x] += w;
        }
    }
    // [1, i] の和を計算.
    T sum(T i)
    {
        T ret = 0;
        for (T x = i; x > 0; x -= x & -x)
        {
            ret += bit[x];
        }
        return ret;
    }
    // [left+1, right] の和を計算.
    T sum(T left, T right)
    {
        return sum(right) - sum(left);
    }
};
int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    string s, t;
    cin >> s >> t;
    ll res ;
    if ((s[s.size() - 1] - '0') % 2 == 0)
    {
        ll temp = 0;
      //  cout<<s<<endl;
        rep(i, s.size() )
        {
            temp += (s[i] - '0');
           // cout<<temp<<endl;
        }
      //  cout<<temp<<endl;
        if (temp % 3 == 0)
        {
            res = 0;
        }
        else if (temp % 3 == 1)
        {
            res = 4;
        }
        else
        {
            res = 2;
        }
    }
    else
    {
        ll temp = 0;
        rep(i, s.size() )
        {
            temp += (s[i] - '0');
        }
        if (temp % 3 == 0)
        {
            res = 3;
        }
        else if (temp % 3 == 1)
        {
            res = 1;
        }
        else
        {
            res = 5;
        }
    }
 //   cout<<res<<endl;
    switch (res)
    {
    case 0:
        cout << 4 << endl;
        break;
    case 1:
        cout << 2 << endl;
        break;
    case 2:
        if ((t[t.size() - 1] - '0') % 2 == 0)
        {
            cout << 7 << endl;
        }
        else
        {
            cout << 8 << endl;
        }
        break;
    case 3:
        cout << 5 << endl;
        break;
    case 4:
        cout << 7 << endl;
        break;
    case 5:
        if ((t[t.size() - 1] - '0') % 2 == 0)
        {
            cout << 2 << endl;
        }
        else
        {
            cout << 1 << endl;
        }
    }
}