#include<cstdio>

 #include<iostream>

 #include<cmath>

 #include<algorithm>

 #include<cstring>

 #include<cstdlib>

 #include<queue>

 #include<vector>

 #include<map>

 #include<stack>

 #include<string>

 using namespace std;

 const long long MOD=;

 long long n,k;

 long long C[][];

 long long dp[][];

 long long dfs(long long x,long long y){

     if (dp[x][y]!=-) return dp[x][y];

     if (x== && y==) return ;

     if (x!= && y==) return ;

     dp[x][y]=;

     for (long long i=;i<=x-y+;i++){

             dp[x][y]=(dp[x][y]+dfs(x-i,y-)*C[x][i]%MOD)%MOD;

     }

     return dp[x][y];

 }

 int main(){

     memset(dp,-,sizeof(dp));

     memset(C,,sizeof(C));

     for (long long i=;i<=;i++) C[i][]=;

     for (long long i=;i<=;i++){

             for (long long j=;j<=;j++){

                     C[i][j]=(C[i-][j]+C[i-][j-])%MOD;

             }

     }

     while (scanf("%lld%lld",&n,&k)==){

             printf("%lld\n",dfs(n,k));

     }

     return ;

 }

 /*

 1 1

 2 2

 */