#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;
    int i = 0;
    while (i < len) {
        y = x->sons[(int)k[i] - 97];
        if (y == NULL) return x;
        x = y;
        i++;
    }
    return x;
}

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

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

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;
}