#include<fstream>
#include<string>
#include<sstream>
#include<cstring>
#include<algorithm>
using namespace std;
typedef struct nod {
	int maxim, minim, mindif, val, h, hdif;
	nod *l, *r;
	nod() { l = 0; r = 0; }
}*avl;
avl root;
string s, s1;
int v, inf = 2000000000;

avl updatemindif(avl root) {

	if (root->l == 0 && root->r == 0) {
		root->maxim = root->val;
		root->minim = root->val;
		root->mindif = inf;
	}
	else if (root->l == 0 && root->r != 0) {
		root->maxim = root->r->maxim;
		root->minim = root->val;
		root->mindif = min(root->r->mindif, root->r->minim - root->val);
	}
	else if (root->l != 0 && root->r == 0) {
		root->maxim = root->val;
		root->minim = root->l->minim;
		root->mindif = min(root->l->mindif, root->val - root->l->maxim);
	}
	else {
		root->maxim = root->r->maxim;
		root->minim = root->l->minim;
		root->mindif = min(min(root->r->minim - root->val, root->val - root->l->maxim), min(root->r->mindif, root->l->mindif));
	}
	return root;

}

avl updatehdif(avl root) {
	if (root->l == 0 && root->r == 0) {
		root->h = 1;
		root->hdif = 0;
	}
	else if (root->l == 0 && root->r != 0) {
		root->h = root->r->h + 1;
		root->hdif = root->r->h;
	}
	else if (root->l != 0 && root->r == 0) {
		root->h = root->l->h + 1;
		root->hdif = -root->l->h;
	}
	else {
		root->h = max(root->l->h, root->r->h) + 1;
		root->hdif = root->r->h - root->l->h;
	}
	return root;

}

avl rotright(avl root) {

	avl aux = root->l;
	root->l = aux->r;
	aux->r = root;

	root = updatehdif(root);
	root = updatemindif(root);

	aux = updatehdif(aux);
	aux = updatemindif(aux);

	return aux;

}

avl rotleft(avl root) {

	avl aux = root->r;
	root->r = aux->l;
	aux->l = root;

	root = updatehdif(root);
	root = updatemindif(root);

	aux = updatehdif(aux);
	aux = updatemindif(aux);

	return aux;

}


avl balance(avl root) {

	root = updatehdif(root);
	root = updatemindif(root);

	if (root->hdif == -2 && root->l->hdif <= 0) root = rotright(root);
	else if (root->hdif == -2 && root->l->hdif == 1) { root->l = rotleft(root->l); root = rotright(root); }
	else if (root->hdif == 2 && root->r->hdif >= 0) root = rotleft(root);
	else if (root->hdif == 2 && root->r->hdif == -1) { root->r = rotright(root->r); root = rotleft(root); }

	return root;
}

avl insert(avl root, int v) {

	if (root == 0) {
		root = new nod;
		root->h = 1;
		root->hdif = 0;
		root->val = v;
		root->maxim = v;
		root->minim = v;
		root->mindif = inf;
		return root;
	}
	else if (v<root->val) {
		root->l = insert(root->l, v);
		return balance(root);
	}
	else if (v>root->val) {
		root->r = insert(root->r, v);
		return balance(root);
	}

	return root;
}

avl sterge(avl root, int v) {

	if (root == 0) return root;

	if (root->val == v) {
		if (root->l == 0 && root->r == 0) return 0;
		else if (root->l == 0 && root->r != 0) return root->r;
		else if (root->l != 0 && root->r == 0) return root->l;

		avl p = root->r;
		while (p->l != 0) p = p->l;

		root->val = p->val;
		root->r = sterge(root->r, p->val);

		return balance(root);

	}
	else if (v<root->val) root->l = sterge(root->l, v);
	else root->r = sterge(root->r, v);

	return balance(root);
}

bool cauta(avl root, int v) {

	if (root == 0) return 0;

	if (v<root->val) return cauta(root->l, v);
	else if (v>root->val) return cauta(root->r, v);
	else return 1;

}

int main(void) {
	ifstream fin("zeap.in");
	ofstream fout("zeap.out");

	getline(fin, s, char(EOF));

	stringstream cin;
	cin << s;

	while (cin >> s1) {
		if (s1[0] == 'I') { 
			              cin >> v; 
						  root = insert(root, v); 
		                  }
		else if (s1[0] == 'C') { 
			              cin >> v; 
						  fout << cauta(root, v) << "\n"; 
		                  }
		else if (s1[0] == 'S') { 
			              cin >> v; 
						  if (cauta(root, v)) root = sterge(root, v); 
						  else fout << "-1\n"; 
		                  }
		else if (s1 == "MIN") { 
			              int aux; 
						  if (root!=0) aux=root->mindif;
						  else aux = inf; 
						  if (aux == inf) aux = -1; 
						  fout << aux << "\n";
		}
		else { 
			int aux;
			if (root != 0) aux = root->maxim - root->minim;
			else aux = 0;
			if (aux == 0) --aux; 
			fout << aux << "\n"; 
		    }

		getline(cin, s1);
	}

	return 0;
}