#include <fstream>

using namespace std;

ifstream fin("trie.in");
ofstream fout("trie.out");

struct Trie
{
        int Cnt,CntKids;
        Trie *kids[26];
        Trie()
        {
                Cnt=CntKids=0;
                for(int i=0;i<26;i++)
                {
                        kids[i]=0;
                }
        }
};

Trie *T=new Trie;

void Insert(Trie *nod,char *s)
{
        if(int(*s)==0)
        {
                nod->Cnt++;
        }
        else
        {
                int Value=*s-'a';
                if(nod->kids[Value]==0)
                {
                        nod->kids[Value]=new Trie;
                        nod->CntKids++;
                }
                Insert(nod->kids[Value],s+1);
        }
}

bool Delete(Trie *nod,char *s)
{
        if(int(*s)==0)
        {
                nod->Cnt--;
        }
        else
        {
                int Value=*s-'a';
                if(Delete(nod->kids[Value],s+1))
                {
                        nod->kids[Value]=0;
                        nod->CntKids--;
                }
        }
        if(nod->Cnt==0 && nod->CntKids==0 && nod!=T)
        {
                delete nod;
                return 1;
        }
        else
        {
                return 0;
        }
}

int GetFrequency(Trie *nod,char *s)
{
        if(int(*s)==0)
        {
                return nod->Cnt;
        }
        else
        {
                int Value=*s-'a';
                if(nod->kids[Value]==0)
                {
                        return 0;
                }
                else
                {
                        return GetFrequency(nod->kids[Value],s+1);
                }
        }
}

int GetLongestPrefix(Trie *nod,char *s,int Dep)
{
        int Value=*s-'a';
        if(int(*s)==0 || nod->kids[Value]==0)
        {
                return Dep;
        }
        else
        {
                return GetLongestPrefix(nod->kids[Value],s+1,1+Dep);
        }
}

int main()
{
        char s[100];
        while(fin.getline(s,100))
        {
                if(s[0]=='0') Insert(T,s+2);
                if(s[0]=='1') Delete(T,s+2);
                if(s[0]=='2') fout<<GetFrequency(T,s+2)<<"\n";
                if(s[0]=='3') fout<<GetLongestPrefix(T,s+2,0)<<"\n";
        }
}