#include <vector>
#include <stdio.h>
#include <cstdlib>
using namespace  std;
struct Treap
{
  long long key;
  long long priority;//rand();
  //long long value=0;
  //long long sum=0;
  Treap* left=nullptr;
  Treap* right=nullptr;

};
/*
long long sum(Treap* t)
{
  if(t==nullptr)
    return 0;
  return t->sum;
}

void update(Treap* t)
{
  t->sum=t->value+sum(t->left)+sum(t->right);
}
*/
Treap* merge(Treap* left, Treap* right)
{
  if(right==nullptr)
  {
    return left;
  }
  if(left==nullptr)
  {
    return right;
  }
  if(left->priority>right->priority)
  {
    left->right=merge(left->right, right);
    //update(left);
    return left;
  }
  right->left=merge(left, right->left);
  //update(right);
  return right;

}
void split(Treap* treap, long long key, Treap*& left, Treap*& right)
{
  if(treap==nullptr)
  {
    left=nullptr;
    right=nullptr;
    return;
  }
  if(treap->key<key)
  {
    split(treap->right, key, treap->right, right);
    left=treap;
  }
  else
  {
    split(treap->left, key, left, treap->right);
    right=treap;
  }
  //update(treap);

}
void GetTree(Treap* treap)
{
  if(treap==nullptr)
  {
    printf("null\n");
    return;
  }
  printf("%lld %lld\n", treap->key, treap->priority);
  GetTree(treap->left);
  GetTree(treap->right);

}

int main()
{
  long long k,p,n;
  scanf("%lld", &n);
  Treap* treap=nullptr;

  for(int i=0;i<n;i++)
  {
    scanf("%lld%lld", &k,&p);
    Treap* node=new Treap;
    node->key=k;
    node->priority=p;
    Treap* left=nullptr;
    Treap* right=nullptr;
    split(treap, k, left,right);
    treap=merge(left, merge(node, right));
  }
  GetTree(treap);
}