#include <bits/stdc++.h>
using namespace std;
int s,n,c[1000004],p[1000004];
struct str
{
int a,b;
bool operator < (const str & o) const
{
if((a-b)<(o.a-o.b)) return true;
return false;
}
};
void print_prio(priority_queue <str> pq)
{
while (!pq.empty())
{
cout << (pq.top()).a << ' ' << (pq.top()).b << endl;
pq.pop();
}
cout << endl;
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
//freopen("22.inp","r",stdin);
//freopen("22.out","w",stdout);
cin>>n;
priority_queue<str> q;
for(int i=1;i<=n;i++) cin>>c[i]>>p[i];
for(int i=1;i<=n;i++)
{
q.push({c[i],p[i]});
s+=c[i];
cout << i << endl;
print_prio(q);
if(i%2!=0)
{
cout << "Pairing " << i << " pilot with someone\n";
str x=q.top();
s=s-(x.a-x.b);
q.pop();
}
}
cout<<s;
}
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