#include <cstdio>

typedef struct nod
{
    int nrfii, nrcuv;
    nod *fiu[30];
} *Trie;
Trie T = new nod;

void insert(Trie &A, char *s)
{
    if(*s == '\n')
    {
        A -> nrcuv++;
        return;
    }

    if(A -> fiu[*s -'a'] == NULL)
    {
        A -> nrfii++;
        A -> fiu[*s - 'a'] = new nod;
    }
    insert(A -> fiu[*s - 'a'], s+1);
}

int del(Trie &A, char *s)
{
    if(*s == '\n')
        A -> nrcuv--;
    else if(del(A -> fiu[*s - 'a'], s+1))
    {
        A -> fiu[*s - 'a'] = 0;
        A -> nrfii--;
    }

    if(A -> nrfii == 0 && A -> nrcuv == 0 && A != T)
    {
        delete A;
        return 1;
    }
    return 0;
}

int app(Trie A, char *s)
{
    if(*s == '\n')
        return A -> nrcuv;
    return app(A -> fiu[*s - 'a'], s+1);
}

int pre(Trie A, char *s)
{
    if((*s == '\n') || (A -> fiu[*s - 'a'] == NULL))
        return 0;
    return pre(A -> fiu[*s - 'a'], s+1) + 1;
}

int main()
{
    freopen("trie.in","rt",stdin);
    freopen("trie.out","wt",stdout);

    char buf[150];
    fgets(buf, sizeof buf, stdin);
    
    while(!feof(stdin))
    {
        switch(buf[0])
        {
            case '0': insert(T, buf+2); break;
            case '1': del(T, buf+2); break;
            case '2': printf("%d\n",app(T, buf+2)); break;
            case '3': printf("%d\n",pre(T, buf+2)); break;
        }
        fgets(buf, sizeof buf, stdin);
    }
}