#include <string.h>
#include <stdio.h>
#define CH (*s - 'a')
struct trie{
    int cnt, nr;
    trie *fiu[26];
    trie(){
        cnt=nr=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->nr++;
    }
    ins(nod->fiu[CH],s+1);
}
bool del(trie *nod, char *s){
    if (*s == '\n')
        nod->cnt--;
    else if (del(nod->fiu[CH],s+1)){
        nod->fiu[CH]=0;
        nod->nr--;
    }
    if (nod->cnt == 0 && nod->nr==0){
            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(){
    char line[50];
    freopen("trie.in","r",stdin);
    freopen("trie.out","w",stdout);

    fgets(line,50,stdin);

    while (!feof(stdin)){
        if (line[0]=='0') ins(T,line+2);
        else if (line[0]=='1') del(T,line+2);
        else if (line[0]=='2') printf("%d\n",que(T,line+2));
        else printf("%d\n",pre(T,line+2,0));

        fgets(line,50,stdin);
    }
}