Help me in solving LOWSUM problem

help
,
1

My issue

It is showing runtime error?

My code

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

int main() {
    int t;
    cin>>t;
    while(t--)
    {
        int k, q;
        cin>>k>>q;
        int a[k], b[k];
        for(int i = 0; i < k; i++)
        {
            cin>>a[i];
        }
        for(int i = 0; i < k; i++)
        {
            cin>>b[i];
        }
        vector<int> sum;
        for(int i = 0; i < k; i++)
        {
            for(int j = 0; j < k; j++)
            {
                sum.push_back(a[i] + b[j]);
            }
        }
        sort(sum.begin(), sum.end());
        while(q--)
        {
            int qi;
            cin>>qi;
            cout<<sum[qi]<<endl;
        }
    }
	return 0;
}

Problem Link: CodeChef: Practical coding for everyone