Doubt on mcq questions

What will be the output of following C++ code?

#include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> pi;
int main()
{
priority_queue<pi , vector, greater >q;
q.push({1, 5});
q.push({5, 3});
q.push({3, 1});
q.push({5, 2});
q.push({1, 10});
cout<<q.top().first<<" "<<q.top().second<<endl;
return 0;
}

Why is the output of thid\s question 15