P1896 互不侵犯

//#define local
#include<cstdio>
#include<iostream>
#include<vector> 
#define MAXN 9
using namespace std;
typedef long long ll; 
int n,sk;
ll dp[MAXN+1][1<<MAXN][MAXN*MAXN+2]={0};
vector<int>s;
vector<int>p;
int count(int i){
	int res=0;
	while(i){
		if(i&1)
		++res;
		i>>=1;
	}
	return res;
}
void init(){
	for(int i=0;i<1<<n;++i){
		if(!(i&i<<1)&&!(i&i>>1)){
			int num=count(i);
			if(num<=sk){
				s.push_back(i);
				p.push_back(num);
			}
		}
	}
}
int main(){
#ifdef local
freopen("data.in","rb",stdin);
//freopen("data.out","wb",stdout);
#endif
scanf("%d%d",&n,&sk);
init();
for(int j=0;j<s.size();++j){
	dp[1][s[j]][p[j]]=1;
}
for(int i=2;i<=n;++i){
	for(int j=0;j<s.size();++j){
		for(int k=p[j];k<=sk;++k){
			for(int w=0;w<s.size();++w)
			if(!(s[w]&s[j])&&!(s[w]>>1&s[j])&&!(s[w]<<1&s[j]))
			dp[i][s[j]][k]+=dp[i-1][s[w]][k-p[j]];
		}
	}
}
ll ans=0;
for(int j=0;j<s.size();++j)
ans+=dp[n][s[j]][sk];
printf("%lld",ans);
return 0;
}