#include <stdio.h>
#include <stdlib.h>
#include <string.h>

struct Elem {
    struct Elem *parent;
    int amount, len, all;
    struct Elem *sons[26];
};

struct Elem *InitTrie()
{
    struct Elem *t = (struct Elem *)malloc(sizeof(struct Elem));
    t->amount = 0;
    t->parent = NULL;
    for (int i = 0; i < 26; i++) t->sons[i] = NULL;
    t->len = 0;
    t->all = 0;
    return t;
}

struct Elem *Descend(struct Elem *t, char *k, int len)
{
    struct Elem *x = t, *y;
    for (int i = 0; i < len; i++) {
        y = x->sons[(int)k[i] - 97];
        if (y == NULL) return x;
        x = y;
    }
    return x;
}

void Insert(struct Elem *t, char *k, int len)
{
    struct Elem *x = Descend(t, k, len);
    int i = x->len, l, j;
    if (i == len) {
        if (x->amount != 1) {
            x->amount = 1;
            struct Elem *y;
            while (1) {
                y = x->parent;
                if (y == NULL) break;
                y->all++;
                x = y;
            }
        }
    }
    else {
        struct Elem *now = x;
        for (j = i + 1; j <= len; j++) {
            struct Elem *y = (struct Elem *)malloc(sizeof(struct Elem));
            y->len = j;
            if (j == len) y->amount = 1;
            else y->amount = 0;
            for (l = 0; l < 26; l++) y->sons[l] = NULL;
            y->all = 0;
            y->parent = x;
            x->sons[(int)k[j - 1] - 97] = y;
            x->all++;
            x = y;
        }
        while (1) {
            x = now->parent;
            if (x == NULL) break;
            x->all++;
            now = x;
        }
    }
}

void Delete(struct Elem *t, char *k, int len)
{
    struct Elem *y, *x = Descend(t, k, len);
    x->amount = 0;
    while (1) {
        y = x->parent;
        if (y == NULL) break;
        y->all--;
        x = y;
    }
}

void SuperFree(struct Elem *t)
{
    if (t != NULL) {
        for (int i = 0; i < 26; i++) SuperFree(t->sons[i]);
        free(t);
    }
}

int main()
{
    int n, i, len;
    char cur[8];
    char now[100000];
    scanf("%d\n", &n);
    struct Elem *t = InitTrie();
    for (i = 0; i < n; i++) {
        scanf("%s ", cur);
        if (0 == strcmp(cur, "INSERT")) {
            scanf("%s", now);
            len = (int)strlen(now);
            Insert(t, now, len);
        }
        if (0 == strcmp(cur, "PREFIX")) {
            scanf("%s", now);
            len = (int)strlen(now);
            struct Elem *x = Descend(t, now, len);
            if (x->len < len) printf("0\n");
            else printf("%d\n", x->amount + x->all);
        }
        if (0 == strcmp(cur, "DELETE")) {
            scanf("%s", now);
            len = (int)strlen(now);
            Delete(t, now, len);
        }
        if (i != n - 1) scanf("\n");
    }
    SuperFree(t);
    return 0;
}