#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define N 100000
#define K 316 /* K = floor(sqrt(N)) */
int max(int a, int b) { return a > b ? a : b; }
int *ei[N], eo[N];
void append(int j, int i) {
int o = eo[j]++;
if (o >= 2 && (o & o - 1) == 0)
ei[j] = (int *) realloc(ei[j], o * 2 * sizeof *ei[j]);
ei[j][o] = i;
}
int main() {
static int iii[N][K], ddd[N][K], ii_[K], dd_[K], dp[N];
static char bad[N];
int n, m, q, g, g1, g2, h, i, j, o;
scanf("%d%d%d", &n, &m, &q);
for (i = 0; i < n; i++)
ei[i] = (int *) malloc(2 * sizeof *ei[i]);
for (h = 0; h < m; h++) {
scanf("%d%d", &i, &j), i--, j--;
append(j, i);
}
for (j = 0; j < n; j++) {
memset(iii[j], -1, K * sizeof *iii[j]), memset(ddd[j], -1, K * sizeof *ddd[j]);
for (o = eo[j]; o--; ) {
i = ei[j][o];
g = 0, g1 = 0, g2 = 0;
while (g < K && (ddd[i][g1] != -1 || ddd[j][g2] != -1))
if (ddd[j][g2] == -1 || ddd[i][g1] != -1 && ddd[i][g1] + 1 > ddd[j][g2])
ii_[g] = iii[i][g1], dd_[g] = ddd[i][g1] + 1, g++, g1++;
else
ii_[g] = iii[j][g2], dd_[g] = ddd[j][g2], g++, g2++;
memcpy(iii[j], ii_, g * sizeof *ii_), memcpy(ddd[j], dd_, g * sizeof *dd_);
}
for (g = 0; g < K; g++)
if (ddd[j][g] == -1) {
iii[j][g] = j, ddd[j][g] = 0;
break;
}
}
while (q--) {
static int ii[N];
int v, k;
scanf("%d%d", &v, &k), v--;
for (h = 0; h < k; h++) {
scanf("%d", &i), i--;
ii[h] = i;
bad[i] = 1;
}
if (k < K) {
g = 0;
while (iii[v][g] != -1 && bad[iii[v][g]])
g++;
printf("%d\n", ddd[v][g]);
} else {
for (j = 0; j < n; j++) {
dp[j] = bad[j] ? -1 : 0;
for (o = eo[j]; o--; ) {
i = ei[j][o];
if (dp[i] != -1)
dp[j] = max(dp[j], dp[i] + 1);
}
}
printf("%d\n", dp[v]);
}
for (h = 0; h < k; h++) {
i = ii[h];
bad[i] = 0;
}
}
return 0;
}
