#include<bits/stdc++.h>
#define endl "\n"
using namespace std;
using ll = long long;
void solve(void)
{
    int n;
    cin>>n;
    int k=(n-1)/3;
    cout<<k<<endl;
    vector<int> even,odd;
    for(int i=k+1;i>=2;i--)
    {
        if(i&1)
        {
            odd.emplace_back(i);
        }
        else
        {
            even.emplace_back(i);
        }
    }
    int mx=0,cnt=k+2;
    for(const auto& a : even)
    {
        int b=cnt;
        cnt++;
        cout<<a<<" "<<b<<" "<<a+b-1<<endl;
        mx=max(mx,a+b-1);
    }
    cnt=mx+1;
    for(const auto& a : odd)
    {
        int b=cnt;
        cnt++;
        cout<<a<<" "<<b<<" "<<a+b-2<<endl;
    }
}
int main(void)
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int t=1;
    while(t--)
    {
        solve();
    }
    return 0;
}