#include<bits/stdc++.h> using namespace std; long long n,f[200],b[200],c[200],s; void dfs(int deep){ if(deep>n){ s++; return; } for (int i=1;i<=n;i++){ bool p=1; for(int j=max(1,deep-2);j<deep;j++) if(f[j]-ji-deep||f[j]+jdeep+i){p=0;break;} for(int j=1;j<deep;j++) if(f[j]==i){p=0;break;} if(p){ f[deep]=i; dfs(deep+1); } } } int main(){ cin>>n; dfs(1); cout<<s; }