#include "bits/stdc++.h"
#include <random>
#define ALL(x) (x).begin(), (x).end()
#define RALL(x) (x).rbegin(), (x).rend()
#define SZ(x) ((lint)(x).size())
#define FOR(i, begin, end) for(lint i=(begin),i##_end_=(end);i<i##_end_;++i)
#define IFOR(i, begin, end) for(lint i=(end)-1,i##_begin_=(begin);i>=i##_begin_;--i)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
#define endk '\n'
using namespace std; typedef unsigned long long _ulong; typedef long long int lint; typedef long double ld; typedef pair<lint, lint> plint; typedef pair<ld, ld> pld;
struct fast_ios { fast_ios() { cin.tie(nullptr), ios::sync_with_stdio(false), cout << fixed << setprecision(10); }; } fast_ios_;
template<class T> auto add = [](T a, T b) -> T { return a + b; };
template<class T> auto mul = [](T a, T b) -> T { return a * b; };
template<class T> auto f_max = [](T a, T b) -> T { return max(a, b); };
template<class T> auto f_min = [](T a, T b) -> T { return min(a, b); };
template<class T> using V = vector<T>;
using Vl = V<lint>; using VVl = V<Vl>; using VVVl = V<V<Vl>>;
template< typename T > ostream& operator<<(ostream& os, const vector< T >& v) {
	for (int i = 0; i < (int)v.size(); i++) os << v[i] << (i + 1 != v.size() ? " " : "");
	return os;
}
template< typename T >istream& operator>>(istream& is, vector< T >& v) {
	for (T& in : v) is >> in;
	return is;
}
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; }
template <class T>
T div_floor(T a, T b) {
	if (b < 0) a *= -1, b *= -1;
	return a >= 0 ? a / b : (a + 1) / b - 1;
}
template <class T>
T div_ceil(T a, T b) {
	if (b < 0) a *= -1, b *= -1;
	return a > 0 ? (a - 1) / b + 1 : a / b;
}
template <class F> struct rec {
	F f;
	rec(F&& f_) : f(std::forward<F>(f_)) {}
	template <class... Args> auto operator()(Args &&... args) const {
		return f(*this, std::forward<Args>(args)...);
	}
};
//lint gcd(lint a, lint b) { if (b == 0) return a; else return gcd(b, a % b); }
lint digit(lint a) { return (lint)log10(a); }
lint e_dist(plint a, plint b) { return abs(a.first - b.first) * abs(a.first - b.first) + abs(a.second - b.second) * abs(a.second - b.second); }
lint m_dist(plint a, plint b) { return abs(a.first - b.first) + abs(a.second - b.second); }
bool check_overflow(lint a, lint b, lint limit) { if (b == 0) return false; return a >= limit / b; } // a * b > c => true
void Worshall_Floyd(VVl& g) { REP(k, SZ(g)) REP(i, SZ(g)) REP(j, SZ(g)) chmin(g[i][j], g[i][k] + g[k][j]); }
const lint MOD1000000007 = 1000000007, MOD998244353 = 998244353, INF = 1e18;
lint dx[8] = { 0, 1, 0, -1, 1, -1, 1, -1 }, dy[8] = { 1, 0, -1, 0, -1, -1, 1, 1 };
bool YN(bool flag) { cout << (flag ? "YES" : "NO") << endk; return flag; } bool yn(bool flag) { cout << (flag ? "Yes" : "No") << endk; return flag; }
struct Edge {
	lint from, to;
	lint cost;
	Edge() {

	}
	Edge(lint u, lint v, lint c) {
		cost = c;
		from = u;
		to = v;
	}
	bool operator<(const Edge& e) const {
		return cost < e.cost;
	}
};
struct WeightedEdge {
	lint to;
	lint cost;
	WeightedEdge(lint v, lint c) {
		to = v;
		cost = c;
	}
	bool operator<(const WeightedEdge& e) const {
		return cost < e.cost;
	}
};
using WeightedGraph = V<V<WeightedEdge>>;
typedef pair<plint, lint> tlint;
typedef pair<ld, ld> pld;
typedef pair<plint, plint> qlint;
typedef pair<char, lint> vstr;
typedef pair<lint, Vl> valv;

std::vector<int> sieve(int n) {
	std::vector<int> res(n);
	std::iota(res.begin(), res.end(), 0);
	for (int i = 2; i * i < n; ++i) {
		if (res[i] < i) continue;
		for (int j = i * i; j < n; j += i)
			if (res[j] == j) res[j] = i;
	}
	return res;
}

std::vector<int> factor(int n, const std::vector<int>& min_factor) {
	// min_factor は sieve() で得られたものとする
	std::vector<int> res;
	while (n > 1) {
		res.push_back(min_factor[n]);
		n /= min_factor[n];
		// 割った後の値についても素因数を知っているので順次求まる
	}
	return res;
}

int main() {
	lint N, M;
	cin >> N >> M;
	M = min(M, N - M);
	plint _cnt = { 0, 0 };
	auto calc = [&](lint val) {
		plint res = { 0, 0 };
		{
			lint curr = 2;
			while (curr <= val) {
				res.first += val / curr;
				curr *= 2;
			}
		}
		{
			lint curr = 5;
			while (curr <= val) {
				res.second += val / curr;
				curr *= 5;
			}
		}
		return res;
	};
	{
		auto p = calc(N);
		_cnt.first += p.first;
		_cnt.second += p.second;
	}
	{
		auto p = calc(N - M);
		_cnt.first -= p.first;
		_cnt.second -= p.second;
	}
	{
		auto p = calc(M);
		_cnt.first -= p.first;
		_cnt.second -= p.second;
	}
	if (min(_cnt.first, _cnt.second) > 8) {
		cout << 0 << endk;
		return 0;
	}
	auto min_f = sieve(N + 1);
	map<lint, lint> cnt;
	REP(i, M) {
		{
			auto fac = factor(N - i, min_f);
			for (auto v : fac) cnt[v]++;
		}
		{
			auto fac = factor(i + 1, min_f);
			for (auto v : fac) cnt[v]--;
		}
	}
	lint ans = 1;
	for (auto p : cnt) {
		REP(i, p.second) {
			ans *= p.first;
			ans %= 100000000;
		}
	}
	string _ans = to_string(ans);
	reverse(ALL(_ans));
	while (SZ(_ans) < 8) _ans += '0';
	reverse(ALL(_ans));
	cout << _ans << endk;
}