#include <stdio.h>
#include <vector>
#include <queue>
#include <algorithm>
#define INF 1000000007
std::vector<int> AdjList[100005];
int Seg[400005];
typedef struct query query;
struct query
{
int i, T;
std::vector<int> Y;
};
std::vector<query> Queries;
int compare(query a, query b)
{
return (a.T < b.T);
}
int Ans[100005];
int Out[100005];
std::vector<int> Topo;
int Pos[100005];
int Longest[100005];
int Vis[100005], cnt;
int N;
int max(int a, int b)
{
return (a > b)?a:b;
}
void makeTree(int s, int e, int cell)
{
if (s == e)
{
Seg[cell] = Longest[s];
return;
}
int m = (s + e)/2;
makeTree(s, m, 2*cell + 1);
makeTree(m + 1, e, 2*cell + 2);
Seg[cell] = max(Seg[2*cell + 1], Seg[2*cell + 2]);
}
void explore(int pos)
{
// printf("explore %d (%d): ", pos, Topo[pos]);
cnt++;
Longest[Topo[pos]] = 0;
Vis[Topo[pos]] = cnt;
int i, u;
while (pos < N)
{
u = Topo[pos];
// printf("u%d\n", u);
if (Vis[u] < cnt)
{
Vis[u] = cnt;
Longest[u] = -INF;
}
for (i = 0; i < AdjList[u].size(); i++)
{
// printf(" v%d\n", AdjList[u][i]);
if (Vis[AdjList[u][i]] < cnt)
{
Vis[AdjList[u][i]] = cnt;
Longest[AdjList[u][i]] = Longest[u] + 1;
}
else if (Longest[u] + 1 > Longest[AdjList[u][i]])
{
Longest[AdjList[u][i]] = Longest[u] + 1;
}
}
pos++;
}
for (i = 1; i <= N; i++)
{
if (Vis[i] < cnt)
{
Vis[i] = cnt;
Longest[i] = -INF;
}
// printf("%d ", Longest[i]);
}
// printf("\n");
makeTree(1, N, 0);
}
void update(int p, int v, int s, int e, int cell)
{
if (s == e)
{
Seg[cell] = v;
return;
}
int m = (s + e)/2;
if (p <= m)
update(p, v, s, m, 2*cell + 1);
else
update(p, v, m + 1, e, 2*cell + 2);
Seg[cell] = max(Seg[2*cell + 1], Seg[2*cell + 2]);
}
int answer(int q)
{
int i;
for (i = 0; i < Queries[q].Y.size(); i++)
update(Queries[q].Y[i], -INF, 1, N, 0);
int r = Seg[0];
for (i = 0; i < Queries[q].Y.size(); i++)
update(Queries[q].Y[i], Longest[Queries[q].Y[i]], 1, N, 0);
if (r < 0)
return -1;
else
return r;
}
int main()
{
int M, Q;
scanf("%d %d %d", &N, &M, &Q);
int i, u, v;
for (i = 0; i < M; i++)
{
scanf("%d %d", &u, &v);
AdjList[v].push_back(u);
Out[u]++;
}
std::queue<int> Qu;
for (i = 1; i <= N; i++)
if (Out[i] == 0)
Qu.push(i);
while (!Qu.empty())
{
u = Qu.front();
Qu.pop();
Pos[u] = Topo.size();
Topo.push_back(u);
for (i = 0; i < AdjList[u].size(); i++)
{
Out[AdjList[u][i]]--;
if (Out[AdjList[u][i]] == 0)
Qu.push(AdjList[u][i]);
}
}
// printf("Topo: ");
// for (i = 0; i < Topo.size(); i++)
// printf("%d ", Topo[i]);
// printf("\n");
int T, Y, j, y;
query p;
for (i = 0; i < Q; i++)
{
scanf("%d %d", &T, &Y);
p.i = i;
p.T = T;
p.Y.clear();
for (j = 0; j < Y; j++)
{
scanf("%d", &y);
p.Y.push_back(y);
}
Queries.push_back(p);
}
std::sort(Queries.begin(), Queries.end(), compare);
for (i = 0; i < Q; i++)
{
if (i == 0 || Queries[i].T != Queries[i - 1].T)
{
explore(Pos[Queries[i].T]);
}
Ans[Queries[i].i] = answer(i);
}
for (i = 0; i < Q; i++)
printf("%d\n", Ans[i]);
}
