#include<bits/stdc++.h> using namespace std; const int N=3e2+10; int dp[N][N]; int main(){ int n,k;scanf("%d%d",&n,&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][2]; else if(j==n) dp[i][j]=dp[i-1][1]+dp[i-1][n-1]; else dp[i][j]=dp[i-1][j-1]+dp[i-1][j+1]; } } printf("%d",dp[k][1]); return 0; } /************************************************************** Problem: 1801 User: liangshinan Language: C++ Result: Accepted Time:162 ms Memory:2452 kb ****************************************************************/