int answer = 0;

priority_queue<int, vector<int>, greater<int>> pq(scoville.begin(), scoville.end());

while (true) {

int a = pq.top();

pq.pop();

if (a >= K) {

return answer;

}

if (pq.empty()) {

return -1;

}

int b = pq.top();

pq.pop();

int result = a < b ? a + (b * 2) : (a * 2) + b;

answer++;

pq.push(result);

}

return -1;

}