#include <bits/stdc++.h> using namespace std; int f(int k) { if(k == 4) { cout << "4,5-->9,10\n"; } else { cout << k << "," << k + 1 << "-->" << 2 * k + 1 << "," << 2 *k + 2 << '\n'; } } int main() { int n; cin >> n; f(n); }