#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <stdbool.h>

typedef struct vector {
    void *head;
    size_t used, capa;
} *vector;

#define vector_make(...) vector_make_overload(__VA_ARGS__, vector_make_2, vector_make_1)(__VA_ARGS__)
#define vector_make_1(bsize) vector_make_(bsize)
#define vector_make_2(type, size) vector_make_(sizeof(type) * (size))
#define vector_make_overload(arg1, arg2, name, ...) name

#define vector_resize(type, vec, size) vector_resize_(vec, sizeof(type) * (size))

#define vector_index(type, vec, index) ((type *)(vec)->head)[index]
#define vector_size(type, vec) ((vec)->used / sizeof(type))
#define vector_push_back(type, vec, value) \
do { \
    vector_resize(type, vec, vector_size(type, vec) + 1); \
    vector_index(type, vec, vector_size(type, vec) - 1) = value; \
} while (0)

vector vector_make_(size_t bsize) {
    vector v = malloc(sizeof(struct vector));

    if (v == NULL) {
        return NULL;
    }

    v->head = malloc(bsize);

    if (v->head == NULL) {
        free(v);
        return NULL;
    }

    v->used = bsize;
    v->capa = bsize;

    return v;
}

bool vector_resize_(vector v, size_t bsize) {
    if (bsize <= v->capa) {
        v->used = bsize;
        return true;
    }

    size_t new_capa = (bsize + v->capa) / (v->capa + 1) * (v->capa + 1);

    void *new = realloc(v->head, new_capa);
    if (new == NULL) {
        return false;
    }

    v->head = new;
    v->used = bsize;
    v->capa = new_capa;

    return true;
}

vector a;
int compare(const void *x, const void *y) {
    return vector_index(int, a, *(int *)x) - vector_index(int, a, *(int *)y);
}

int main() {
    int n, m;
    scanf("%d %d", &n, &m);

    a = vector_make(int, n);
    for (int i = 0; i < n; ++i) {
        scanf("%d", &vector_index(int, a, i));
    }

    vector g = vector_make(vector, n);
    for (int i = 0; i < n; ++i) {
        vector_index(vector, g, i) = vector_make(int, 0);
    }

    for (int i = 0; i < m; ++i) {
        int u, v;
        scanf("%d %d", &u, &v);
        --u; --v;

        vector_push_back(int, vector_index(vector, g, u), v);
        vector_push_back(int, vector_index(vector, g, v), u);
    }

    vector lamp = vector_make(bool, n);
    for (int i = 0; i < n; ++i) {
        vector_index(bool, lamp, i) = false;
    }

    int k;
    scanf("%d", &k);

    for (int i = 0; i < k; ++i) {
        int b;
        scanf("%d", &b);
        --b;
        vector_index(bool, lamp, b) = true;
    }

    vector x = vector_make(int, 0);

    vector index = vector_make(int, n);
    for (int i = 0; i < n; ++i) {
        vector_index(int, index, i) = i;
    }

    qsort(&vector_index(int, index, 0), n, sizeof(int), &compare);
    for (int i = 0; i < n; ++i) {
        int idx = vector_index(int, index, i);

        if (!vector_index(bool, lamp, idx)) {
            continue;
        }

        vector_push_back(int, x, idx);

        vector list = vector_index(vector, g, idx);

        vector_index(bool, lamp, idx) = false;
        for (int j = 0; j < vector_size(int, list); ++j) {
            int v = vector_index(int, list, j);

            if (vector_index(int, a, idx) < vector_index(int, a, v)) {
                vector_index(bool, lamp, v) ^= 1;
            }
        }
    }

    printf("%zu\n", vector_size(int, x));
    for (int i = 0; i < vector_size(int, x); ++i) {
        printf("%d\n", vector_index(int, x, i) + 1);
    }
}