60分求调，为什么最后总是有三个TLE

123456789101112131415161718192021222324252627#include<bits/stdc++.h>
#define us unsigned long long//我的数据结构还不行吗？
using namespace std;
priority_queue<us,vector<us>,greater<us>> q;
int main(){
	ios::sync_with_stdio(0);
	cin.tie();
	cout.tie();
	us n,sum=0;
	cin>>n;
	for(us i=1;i<=n;i++){
		us x;
		cin>>x;
		q.push(x);
	}
	while(q.size()>1){
		us a=q.top();
		q.pop();
		us b=q.top();
		q.pop();
		sum+=a;
		sum+=b;
		q.push(a+b);
	}
	cout<<sum;
	return 0;
}