#include<cstdio>
#include<cstring>
#define CH (*s-'a')
using namespace std;
struct Trie{
    int cnt,nrfii;
    Trie *fiu[26];
    Trie(){
        cnt=nrfii=0;
        memset(fiu,0,sizeof(fiu));
    }
};
Trie *T=new Trie;
void ins(Trie *nod, char *s){
    if(*s=='\n'){
        nod->cnt++; return;
    }
    if(nod->fiu[CH]==0){
        nod->fiu[CH]=new Trie;
        nod->nrfii++;
    }
    ins(nod->fiu[CH], s+1);
}
int del(Trie *nod, char *s){
    if(*s=='\n') nod->cnt--;
    else if(del(nod->fiu[CH], s+1)){
        nod->fiu[CH]=0;
        nod->nrfii--;
    }
    if(nod->cnt==0 && nod->nrfii==0 && nod!=T){
        delete nod; return 1;
    }
    return 0;
}
int que( Trie *nod, char *s){
    if(*s=='\n') return nod->cnt;
    if(nod->fiu[CH]) return que(nod->fiu[CH], s+1);
    return 0;
}
int pre( Trie *nod, char *s, int k){
    if(*s=='\n' || nod->fiu[CH]==0) return k;
    return pre(nod->fiu[CH], s+1, k+1);
}
int main(){
    freopen("trie.in","r",stdin);
    freopen("trie.out","w",stdout);
    char line[32];
    fgets(line,32,stdin);
    while(!feof(stdin)){
        switch(line[0]){
            case '0': ins(T, line+2); break;
            case '1': del(T, line+2); break;
            case '2': printf("%d\n", que(T,line+2)); break;
            case '3': printf("%d\n", pre(T,line+2,0)); break;
        }
        fgets(line,32,stdin);
    }
    return 0;

}