#ARCH_2 Standard_Trie

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

#define ALPHA_SIZE 26

struct vertex {
    char *v;
    struct vertex *parent, *arcs[ALPHA_SIZE];
} *t;

int m;

struct vertex *InitTrie()
{
    struct vertex *x;
    int i;
    x = (struct vertex*)malloc(sizeof(struct vertex));
    for (i = 0; i < ALPHA_SIZE; i++)
        x->arcs[i] = NULL;
    x->v = NULL;
    return x;
}

struct vertex *Descend(char *k)
{
    int len = strlen(k);
    struct vertex *x, *y;
    x = t;
    m = 0;
    while (m < len) {
        y = x->arcs[k[m] – 'a'];
        if (0 == y) break;
        x = y; m++;
    }
    return x;
}

void Delete (char *k)
{
    struct vertex *x;
    x = Descend(k);
    x->v = NULL;
}

void Lookup (char *k)
{
    int i, len = strlen(k);
    struct vertex *x;
    x = Descend(k);
    i = m;
    if (x->v == NULL)
        printf("element does not exist\n");
    printf("%s\n", x->v);
}

void Insert (char *k, char *value)
{
    int i, len = strlen(k);
    struct vertex *x, *y;
    x = Descend(k);
    x->v = value;
}

int main()
{
    int i, n;
    char command[10], str[100], value[100];
    struct vertex *x;
    t = InitTrie();
    scanf("%d", &n);
    for (i = 0; i < n; i++) {
        scanf("%s", command);
        if ('i' == command[0]) { //insert
            scanf("%s%s", str, value);
            Insert(str, value);
        }
        if ('d' == command[0]) { //delete
            scanf("%s", str); Delete(str);
        }
        if ('l' == command[0]) { //lookup
            scanf("%s", str); Lookup(str);
        }
    }
    return 0;
}