/* upsolve after reading spoiler */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define N 250000
#define M 3000000
#define K 2750
#define L 1500
#define N_ (N + K * L)
#define INF 0x3f3f3f3f
int min(int a, int b) { return a < b ? a : b; }
int dd[N_], pq[N_], iq[1 + N_], cnt;
int lt(int i, int j) { return dd[i] < dd[j]; }
int p2(int p) {
return (p *= 2) > cnt ? 0 : (p < cnt && lt(iq[p + 1], iq[p]) ? p + 1 : p);
}
void pq_up(int i) {
int p, q, j;
for (p = pq[i]; (q = p / 2) && lt(i, j = iq[q]); p = q)
iq[pq[j] = p] = j;
iq[pq[i] = p] = i;
}
void pq_dn(int i) {
int p, q, j;
for (p = pq[i]; (q = p2(p)) && lt(j = iq[q], i); p = q)
iq[pq[j] = p] = j;
iq[pq[i] = p] = i;
}
void pq_add_last(int i) {
iq[pq[i] = ++cnt] = i;
}
int pq_remove_first() {
int i = iq[1], j = iq[cnt--];
if (j != i)
pq[j] = 1, pq_dn(j);
pq[i] = 0;
return i;
}
int *ej[N], eo[N];
void append(int i, int j) {
ej[i][eo[i]++] = j;
}
void update(int i, int d) {
if (dd[i] > d) {
if (dd[i] == INF)
pq_add_last(i);
dd[i] = d, pq_up(i);
}
}
int main() {
static int uu[M], vv[M], gg[N], hh[N], ll[K], ii[K][L], iil[N], iir[N], idx[N_];
int n, n_, m, k, g, g_, h, i, j;
scanf("%d%d", &n, &m);
for (h = 0; h < m; h++) {
scanf("%d%d", &uu[h], &vv[h]), uu[h]--, vv[h]--;
eo[uu[h]]++, eo[vv[h]]++;
}
for (i = 0; i < n; i++)
ej[i] = (int *) malloc(eo[i] * sizeof *ej[i]), eo[i] = 0;
for (h = 0; h < m; h++)
append(uu[h], vv[h]), append(vv[h], uu[h]);
scanf("%d", &k);
memset(gg, -1, n * sizeof *gg);
for (g = 0; g < k; g++) {
scanf("%d", &ll[g]);
for (h = 0; h < ll[g]; h++) {
scanf("%d", &i), i--;
ii[g][h] = i;
gg[i] = g, hh[i] = h;
}
}
n_ = 0;
for (i = 0, n_ = 0; i < n; i++) {
if (gg[i] == -1)
iil[i] = n_, iir[i] = n_ + 1;
else
iil[i] = n_, iir[i] = n_ + ll[gg[i]];
while (n_ < iir[i])
idx[n_++] = i;
}
memset(dd, 0x3f, n_ * sizeof *dd);
dd[0] = 0, pq_add_last(0);
while (cnt) {
int i_, d, d_, d1, p, q, o, o_;
i_ = pq_remove_first(), i = idx[i_], g = gg[i], h = hh[i], d = dd[i_];
if (i == n - 1) {
printf("%d\n", d);
return 0;
}
if (g == -1) {
for (o = eo[i]; o--; ) {
j = ej[i][o], g_ = gg[j];
if (g_ == -1)
update(iil[j], d + 1);
else {
d_ = (d - hh[j] + ll[g_]) / ll[g_] * ll[g_] + hh[j];
if ((d + 1) % ll[g_] != hh[j])
update(iil[j] + (d + 1) % ll[g_], d + 1);
update(iil[j] + (d_ + 1) % ll[g_], d_ + 1);
}
}
} else {
if ((d + 1) % ll[g] != h)
update(iil[i] + (d + 1) % ll[g], d + 1);
p = ii[g][(h - 1 + ll[g]) % ll[g]], q = ii[g][(h + 1) % ll[g]];
for (o = 0, o_ = 0; o < eo[i]; o++) {
j = ej[i][o], g_ = gg[j];
if (g_ == -1)
update(iil[j], d + 1);
else if (j == q) {
update(iil[j] + (d + 1) % ll[g_], d + 1);
ej[i][o_++] = j;
} else if (j == p) {
if ((d + 1) % ll[g_] != hh[j] && (d + 1) % ll[g_] != h)
update(iil[j] + (d + 1) % ll[g_], d + 1);
ej[i][o_++] = j;
} else {
d_ = (d - hh[j] + ll[g_]) / ll[g_] * ll[g_] + hh[j];
if ((d + 1) % ll[g_] != hh[j])
update(iil[j] + (d + 1) % ll[g_], d + 1);
if (d_ % ll[g] == h) {
d1 = d + (d_ - d + ll[g]) / ll[g] * ll[g];
d_ = (d1 - hh[j] + ll[g_]) / ll[g_] * ll[g_] + hh[j];
if ((d1 + 1) % ll[g_] != hh[j])
update(iil[j] + (d1 + 1) % ll[g_], d1 + 1);
ej[i][o_++] = j;
}
if (d_ % ll[g] != h)
update(iil[j] + (d_ + 1) % ll[g_], d_ + 1);
}
}
eo[i] = o_;
}
}
printf("impossible\n");
return 0;
}
