Forth

#include <iostream>
using namespace std;

int bitwidth(int x) {
	int r = 0;
	while (x >>= 1) { r++; }
	return r;
}

int main() {
	int num;
	cin >> num;
	int bits = __builtin_popcount(num);
	int width = bitwidth(num);

	cout << width * 2 + bits * 2 - 2 << endl;

	int b=1;
	while ((b+b)<=num) {
		if (b & num) cout << "DUP ";
		cout << "DUP + ";
		b<<=1;
	}

	while (bits>1) {
		cout << "+ ";
		bits--;
	}
	cout << endl;
	return 0;
}

Test 1

Verdict: WRONG ANSWER

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