#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
// typedef unsigned long long ull;
// const ll INF = numeric_limits<ll>::max() / 4;
// const int INF = numeric_limits<int>::max() / 4;
// cout << std::fixed << std::setprecision(15);


int main() {
	ll N; int E;
	cin >> N >> E;
	int K = 20;
	ll EPS = 1;
	for(int i = 0; i < K; i++) EPS *= 5;
	if(N < 0) N += EPS;
	vector<ll> T(K, 0);
	for(int k = 0; k < K; k++){
		T[k] = N % 5LL;
		N /= 5;
	}
	vector<ll> R(K, 0);
	vector<ll> U(K, 0);
	for(int e = 0; e < E; e++){
		ll l = U[e];
		U[e] = 0;
		for(int j = 1; j <= e - 1; j++){
			l += R[j] * R[e - j];
		}
		bool f = false;
		for(R[e] = 0; R[e] < 5; R[e]++){
			ll s = R[e] * R[0] * 2;
			if(e == 0) s = R[0] * R[0];
			if((l + s) % 5 == T[e]){
				l += s;
				l /= 5;
				for(int j = e + 1; j < K; j++){
					U[j] += l % 5;
					l /= 5;
				}
				f = true;
				break;
			}
		}
		if(!f){
			cout << "NaN" << endl;
			return 0;
		}
	}

	ll r = 0;
	ll d = 1;
	for(int k = 0; k <= K; k++){
		r += R[k] * d;
		d *= 5LL;
	}

	cout << r << endl;
	return 0;
}