#include<bits/stdc++.h>
using namespace std;
#define rep(i,x,y) for (int i=(x);i<=(y);i++)
#define drep(i,y,x) for (int i=(y);i>=(x);i--)
#define pii pair<int,int>
#define fir first
#define sec second
#define MP make_pair
#define templ template<typename T>
templ bool chkmin(T &x,T y){return x>y?x=y,1:0;}
templ bool chkmax(T &x,T y){return x<y?x=y,1:0;}
void file() {
    #ifdef zqj
    freopen("a.in","r",stdin);
    #endif
}
typedef long long ll;

int n;
int vis[1010000];

int main() {
    file();
    ios::sync_with_stdio(false),cin.tie(0);
    cin>>n;
    while (n%3!=1) --n;
    int r=(n-1)/3+1;
    cout<<n/3<<'\n';
    while (r!=1) {
        int len=r/2,t=0;
        drep(i,r,r-len+1) {
            int x=i,y=n-len-t,z=n-t;
            assert(z<x+y&&1ll*z*z>1ll*x*x+1ll*y*y);
            assert(!vis[x]&&!vis[y]&&!vis[z]);
            vis[x]=vis[y]=vis[z]=1;
            cout<<i<<' '<<n-len-t<<' '<<n-t<<'\n',++t;
        }
        r-=len;
        n-=len*2;
    }
    return 0;
}