#include<fstream>
#include<algorithm>
#include<cstdlib>
#include<ctime>
#include<cstring>
#define inf 0x3f3f3f3f

using namespace std;

ifstream f("zeap.in");
ofstream g("zeap.out");

struct Treap
{
	int ma,mi,mad,mid,key,pr;
	Treap *lef, *rig;
	Treap() {}
	Treap(int _ma,int _mi,int _mad,int _mid,int _key,int _pr,Treap *_lef,Treap *_rig)
	{
		ma=_ma;
		mi=_mi;
		mad=_mad;
		mid=_mid;
		key=_key;
		pr=_pr;
		lef=_lef;
		rig=_rig;
	}
};

Treap *R,*nil;

void init()
{
	srand(time(0));
	R=nil=new Treap(-inf,inf,-inf,inf,0,0,NULL,NULL);
	nil->lef=nil->rig=nil;
}

void upd(Treap* &nod)
{
	nod->mi=min(nod->key,min(nod->lef->mi,nod->rig->mi));
	nod->ma=max(nod->key,max(nod->lef->ma,nod->rig->ma));
	
	nod->mid= min(min(nod->lef->mid, nod->rig->mid) ,min( nod->key - nod->lef->ma , nod->rig->mi - nod->key ));
	nod->mad= max(nod->ma - nod->mi,max(nod->lef->mad,nod->rig->mad));
}

void rotlef(Treap* &nod)
{
	Treap *t= nod->lef;
	nod->lef=t->rig;
	t->rig=nod;
	nod=t;
	
	upd(nod);
	upd(nod->rig);
}

void rotrig(Treap* &nod)
{
	Treap *t = nod->rig;
	nod->rig=t->lef;
	t->lef=nod;
	nod=t;
	
	upd(nod);
	upd(nod->lef);
}

void balance(Treap* &nod)
{
	if(nod->lef->pr > nod->pr) rotlef(nod);
	if(nod->rig->pr > nod->pr) rotrig(nod);
}

int find(Treap *nod,int key)
{
	if(nod==nil) return 0;
	if(nod->key == key) return 1;
	if(nod->key < key) return find(nod->rig,key);
	return find(nod->lef,key);
}

void insert(Treap* &nod, int key, int pr)
{
	if(nod==nil)
	{
		nod=new Treap(key,key,-inf,inf,key,pr,nil,nil);
		return ;
	}
	
	if(key < nod->key) insert(nod->lef,key,pr);
	else
		insert(nod->rig,key,pr);
	
	balance(nod);
	upd(nod);
}

void erase(Treap* &nod, int key)
{
	if(nod==nil) return ;
	if(key==nod->key)
	{
		if(nod->lef==nil&&nod->rig==nil)
		{
			delete(nod);
			nod=nil;
			return;
		}
		if(nod->lef->pr > nod->rig->pr)
		{
			rotlef(nod);
			erase(nod->rig,key);
		}
		else
		{
			rotrig(nod);
			erase(nod->lef,key);
		}
	}
	else
	{
		if(key>nod->key) 
			erase(nod->rig,key);
		else
			erase(nod->lef,key);
	}
	upd(nod);
}

int main ()
{
	int x;
	string s;
	init();
	
	while(f>>s)
	{
		if(s=="C")
		{
			f>>x;
			g<<find(R,x)<<"\n";
		}
		else
		if(s=="I")
		{
			f>>x;
			if(!find(R,x))
			insert(R,x,rand()+1);
		}
		else
		if(s=="S")
		{
			f>>x;
			if(!find(R,x))
				g<<"-1\n";
			else
				erase(R,x);
		}
		else
		if(s=="MAX")
		{
			if(R->mad>-inf)
				g<<R->mad<<"\n";
			else
				g<<"-1\n";
		}
		else
		{
			if(R->mid<inf)
				g<<R->mid<<"\n";
			else
				g<<"-1\n";
		}
	}
	return 0;
}