#include <stdio.h>

struct elem
{
    struct elem **arr;
    int pref;
    int x;
}*t;

struct elem * buildtree()
{
    t = (struct elem*)calloc(1, sizeof(struct elem));
    t->arr = (struct elem**)calloc(35, sizeof(struct elem*));
    t->x = 0;
    t->pref = 0;
    return t;
}

int insert(struct elem* t, char *s)
{
    int x = 0;
    if (!*s)
    {
        if (!t->x)
        {
            t->pref++;
            t->x++;
            return 1;
        }
    }
    else
    {
        x = s - 'a';
        if (!t->arr[x])
            t->arr[x] = buildtree();
        struct elem *temp = t->arr[x];
        if (insert(temp, s + 1))
        {
            t->pref++;
            return x + 1;
        }

    }
}

int delete(struct elem* t, char *s)
{
    if (t)
    {
        if (*s != NULL)
        {
            int j = s - 'a';
            struct elem *temp = t->arr[j];
            if (delete(temp, s + 1))
            {
                t->pref--;
                return 1;
            }
        }
        else
        {
            if (t->x)
            {
                t->x--;
                t->pref--;
                return 1;
            }
        }
    }
    return 0;
}

void check(char *command, char * w)
{
    if (command[0] == 'I')
    {
        insert(t, w);
        return 0;
    }
    if (command[0] == 'P')
    {
        int res = pref(t, w);
        printf("%d", res);
        return 0;
    }
    if (command[0] == 'D')
    {
        delete(t, w);
        return 0;
    }
}

int pref(struct elem* t, char *s)
{
    int x = 0;
    if(t)
    {
        if( *s)
        {
            x = s - 'a';
            struct elem *temp = t->arr[x];
            return pref(temp, s + 1);
        }
        else
            return t->pref;
    }
    return 0;
}

int main()
{
    int n;
    scanf("%d", &n);
    t = buildtree();
    for (int i = 0; i < n; i++)
    {
        char *w = (char*)malloc(sizeof(char)*100100);
        char command[7];
        scanf("%s", command);
        scanf("%s", w);
        check(command, w);
        free(w);
    }

    return 0;
}