C++ :

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <set>
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define space putchar(' ')
#define enter putchar('\n')
typedef pair<int,int> PII;
const int mod=1e4+7;
const int N=2e6+10;
const int inf=0x7f7f7f7f;


ll gcd(ll a,ll b)
{
    return b==0?a:gcd(b,a%b);
}

ll lcm(ll a,ll b)
{
    return a*(b/gcd(a,b));
}

template <class T>
void read(T &x)
{
    char c;
    bool op = 0;
    while(c = getchar(), c < '0' || c > '9')
        if(c == '-')
            op = 1;
    x = c - '0';
    while(c = getchar(), c >= '0' && c <= '9')
        x = x * 10 + c - '0';
    if(op)
        x = -x;
}
template <class T>
void write(T x)
{
    if(x < 0)
        x = -x, putchar('-');
    if(x >= 10)
        write(x / 10);
    putchar('0' + x % 10);
}

int fa[N];
int n,k;
PII a[N],sum[N];
int dp[50][50];
int main()
{
   read(n),read(k);
   dp[0][1]=1;
   for(int i=1;i<=k;i++)
   {
       for(int j=1;j<=n;j++)
       {
           if(j==1)
            dp[i][j]=dp[i-1][n]+dp[i-1][j+1];
           else if(j==n)
            dp[i][j]=dp[i-1][n-1]+dp[i-1][1];
           else
           dp[i][j]=dp[i-1][j-1]+dp[i-1][j+1];
       }
   }
   write(dp[k][1]);






    return 0;
}