Forth

#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);

  int x;
  cin >> x;

  vector<string> r;
  for (int i = 0; i < x - 1; ++i) r.push_back("DUP");
  for (int i = 0; i < x - 1; ++i) r.push_back("+");

  r.push_back("DUP");
  r.push_back("DROP");

  cout << r.size() << endl;
  for (string s : r) cout << s << " ";
  cout << endl;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED