#include "bits/stdc++.h" using namespace std; #define int long long #define FOR(i, a, b) for(int i=(a);i<(b);i++) #define RFOR(i, a, b) for(int i=(b-1);i>=(a);i--) #define REP(i, n) for(int i=0; i<(n); i++) #define RREP(i, n) for(int i=(n-1); i>=0; i--) #define REP1(i, n) for(int i=1; i<=(n); i++) #define RREP1(i, n) for(int i=(n); i>=1; i--) #define ALL(a) (a).begin(),(a).end() #define UNIQUE_SORT(l) sort(ALL(l)); l.erase(unique(ALL(l)), l.end()); #define CONTAIN(a, b) find(ALL(a), (b)) != (a).end() #define out(...) printf(__VA_ARGS__) int dxy[] = {0, 1, 0, -1, 0}; void solve(); signed main() { #if DEBUG std::ifstream in("input.txt"); std::cin.rdbuf(in.rdbuf()); #endif cin.tie(0); ios::sync_with_stdio(false); solve(); return 0; } /*================================*/ #if DEBUG #define SIZE 100 #else #define SIZE 123450 #endif int N,M; vector primes; map C; int COM(int n, int k) { REP1(i,k) { int a = n-i+1; int b = i; for (int p:primes) { while(a%p==0) C[p]++, a/=p; while(b%p==0) C[p]--, b/=p; } if (a>1) C[a]++; if (b>1) C[b]--; } while(C[2]>=9 && C[5]>=9) { C[2] -= 9; C[5] -= 9; } int r = 1; for (auto p:C) { if (p.second) r *= p.first * p.second; } return r; } void solve() { cin>>N>>M; N /= 1000; N %= M; FOR(i,2,10000) { bool is_p = true; for (int p:primes) if (i%p==0) { is_p = false; break; } if (is_p) primes.push_back(i); } cout << COM(M,N) << endl; }