//#include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>
using namespace std;

void format_word(char *s)
{
    char *p=strchr(s,'\n');
    if(p) *p=0;
}

class Trie {

public:
    int val;
    int nrFii;
    Trie* Fiu[26];

    Trie() {
        val=nrFii=0;
        memset(Fiu,0,sizeof(Fiu));
    }

    void pushRec(char *s) { ///RECURSIV
        if(*s=='\0') {
            val++;
            return ;
        }

        int x=*s-'a';
        if(Fiu[x]==NULL)
        {
            Fiu[x]=new Trie();
            nrFii++;
        }

        Fiu[x]->pushRec(s+1);
    }

    void push(char *s) {  ///iterativ
        Trie *T=this;

        while(*s) {
            int x=*s-'a';
            if(T->Fiu[x]==0) {
                T->Fiu[x]=new Trie();
                T->nrFii++;
            }
            T=T->Fiu[x];
            s++;
        }

        T->val++;

    }

    void rmv(char *s) {

        if(*s=='\0') {if(val>0) val--; return ;}

        int x=*s-'a';
        if(Fiu[x]==0) return;

        Fiu[x]->rmv(s+1);

        if(Fiu[x]->nrFii==0 && Fiu[x]->val==0) {
            delete Fiu[x];
            Fiu[x]=0;
            nrFii--;
        }

    }

    int countREC(char *s) { ///REC

        if(*s=='\0') return val;

        int x=*s-'a';
        if(*s!='\0' && Fiu[x]==0) return 0;

        return Fiu[x]->countREC(s+1);

    }

    int count(char *s) {
        Trie *T=this;
        while(*s) {
            int x=*s-'a';
            if(T->Fiu[x]==0) return 0;
            s++;
            T=T->Fiu[x];
        }
        return T->val;
    }

    int longest_prefix(char *s) {
        Trie *T=this;
        int i=0;
        while(s[i]) {
            int x=s[i]-'a';
            if(T->Fiu[x]==0) break;
            i++;
            T=T->Fiu[x];
        }

        return i;
    }

};

int main()
{
    freopen("trie.in", "r", stdin);
    freopen("trie.out", "w", stdout);

    char line[32];
    Trie T= Trie();
    while(fgets(line,32,stdin)) {

        format_word(line+2);
        switch(line[0])
        {
            case '0': T.push(line+2); break;
            case '1': T.rmv(line+2); break;
            case '2': printf("%d\n", T.count(line+2)); break;
            case '3': printf("%d\n", T.longest_prefix(line+2)); break;
        }

    }

    return 0;
}