#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define X first
#define Y second
#define SZ(a) ((int)a.size())
#define ALL(v) v.begin(), v.end()
#define pb push_back

struct Tuple {
    int x, y, z;
    void check() const {
        assert(x < y && y < z);
        assert(x + y > z);
        assert((ll)x * x + (ll)y * y < (ll)z * z);
    }
};

vector<Tuple> solve(int n) {
    if (n <= 3) return {};
    while (n % 3 != 1) --n;
    if (n == 7) {
        vector<Tuple> result;
        result.push_back({2, 4, 5});
        result.push_back({3, 6, 7});
        return result;
    }
    if (n == 10) {
        vector<Tuple> result;
        result.push_back({2, 4, 5});
        result.push_back({3, 8, 9});
        result.push_back({6, 7, 10});
        return result;
    }
    if (n == 19) {
        vector<Tuple> result;
        result.push_back({2, 3, 4});
        result.push_back({5, 6, 8});
        result.push_back({7, 11, 15});
        result.push_back({9, 14, 17});
        result.push_back({12, 13, 18});
        result.push_back({10, 16, 19});
        return result;
    }
    auto result = solve(n / 3);
    int req = n / 3 - (int)result.size();
    for (int i = req - 1; i >= 0; --i) {
        result.push_back({n - i - req * 2, n - i - req, n - i});
    }
    return result;
}

int main() {
    ios::sync_with_stdio(0), cin.tie(0);
    int n;
    cin >> n;
    auto ans = solve(n);
    cout << ans.size() << endl;
    // set<int> st;
    for (const auto &tri : ans) {
        tri.check();
        cout << tri.x << ' ' << tri.y << ' ' << tri.z << '\n';
        /*
        st.insert(tri.x);
        st.insert(tri.y);
        st.insert(tri.z);
        */
    }
    // assert(st.size() == ans.size() * 3);
    return 0;
}