#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")

#include <bits/stdc++.h>

using namespace std;
using ll = long long;

const ll mod = 1e9 + 7;
const ll mod2 = 998244353;

ll gcd(ll a, ll b) {
    return b ? gcd(b, a % b) : a;
}

ll pow(ll a, ll b) {
    ll ans = 1;
    while (b) {
        if (b & 1) ans *= a;
        b >>= 1;
        a *= a;
    }
    return ans;
}

ll pow(ll a, ll b, ll c) {
    ll ans = 1;
    while (b) {
        if (b & 1) ans = (ans * a) % c;
        b >>= 1;
        a = (a * a) % c;
    }
    return ans;
}

void check(bool b) {
    if (b)
        cout << "Yes\n";
    else
        cout << "No\n";
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int t = 1;
//    cin >> t;
    while (t--) {
        string n;ll b;
        cin>>n>>b;
        if (b==1){
            cout<<0<<'\n';
            return 0;
        }
        ll x=0;
        for (int i = 0; i < n.size(); ++i) {
            x*=10;
            x+=n[i]-'0';
            x%=b;
//            cout<<x<<' ';
        }
//        cout<<'\n';
        ll ans=0;
        while (ans<b && (x*ans)%b!=1)++ans;
        if (ans==b){
            cout<<"NaN"<<'\n';
            return 0;
        }
        cout<<ans<<'\n';
    }
    return 0;
}