#include <bits/stdc++.h>
#define int long long
#define mid ((l+r)>>1)
#define lowbit(i) (i&(-i))
using namespace std;
signed main(){
	ios::sync_with_stdio(false);
	cin.tie(0),cout.tie(0);
	int n; cin>>n;
	n--;
	int p=n/3;
	cout<<p<<"\n";
	if(p&1){
		for(int i=p,j=0;i>=3;i-=2,j++){
			cout<<i<<" "<<p+j+2<<" "<<2*p-j<<"\n";
		}
		for(int i=p+1,j=0;i>=2;i-=2,j++){
			cout<<i<<" "<<2*p+j+1<<" "<<3*p-j+1<<"\n";
		}
	}
	else{
		for(int i=p,j=0;i>=2;i-=2,j++){
			cout<<i<<" "<<p+j+2<<" "<<2*p+1-j<<"\n";
		}
		for(int i=p+1,j=0;i>=3;i-=2,j++){
			cout<<i<<" "<<2*p+j+2<<" "<<3*p+1-j<<"\n";
		}
	}
	return 0;
}