#include <iostream>
#include <algorithm>
#include <vector>
struct Beaver
{
Beaver(int i, int d) : id(i), dist(d) {}
int id, dist;
};
const int MAXN = 1e5;
const int SQRT = 317;
std::vector<int> graph[MAXN];
std::vector<Beaver> furthest[MAXN];
bool seen[MAXN];
bool busy[MAXN];
int maxDist[MAXN];
void append(std::vector<Beaver> &vec, Beaver elem)
{
if (!seen[elem.id])
{
vec.emplace_back(elem);
seen[elem.id] = true;
}
}
void merge(int parent, int child)
{
std::vector<Beaver> merged;
int left = 0, right = 0;
while (merged.size() < SQRT && (left < (int)furthest[parent].size() || right < (int)furthest[child].size()))
{
if (left == (int)furthest[parent].size())
{
append(merged, Beaver(furthest[child][right].id, furthest[child][right].dist + 1));
right++;
}
else if (right == (int)furthest[child].size())
{
append(merged, furthest[parent][left]);
left++;
}
else if (furthest[parent][left].dist > furthest[child][right].dist + 1)
{
append(merged, furthest[parent][left]);
left++;
}
else
{
append(merged, Beaver(furthest[child][right].id, furthest[child][right].dist + 1));
right++;
}
}
for (Beaver beav : merged)
seen[beav.id] = false;
furthest[parent] = merged;
}
int slowcheck(int node)
{
if (seen[node])
return maxDist[node];
seen[node] = true;
if (busy[node])
maxDist[node] = -1;
else
maxDist[node] = 0;
for (int child : graph[node])
{
int sub = slowcheck(child);
if (sub != -1)
maxDist[node] = std::max(maxDist[node], sub + 1);
}
return maxDist[node];
}
int main()
{
std::ios::sync_with_stdio(false);
std::cout.tie(nullptr);
std::cin.tie(nullptr);
int nodes, edges, queries;
std::cin >> nodes >> edges >> queries;
for (int iEdge = 0; iEdge < edges; iEdge++)
{
int u, v;
std::cin >> u >> v;
graph[v - 1].emplace_back(u - 1);
}
for (int iNode = 0; iNode < nodes; iNode++)
{
furthest[iNode].emplace_back(iNode, 0);
for (int child : graph[iNode])
merge(iNode, child);
}
for (int iQuery = 0; iQuery < queries; iQuery++)
{
int location, unable;
std::cin >> location >> unable;
location--;
std::vector<int> notComing;
for (int iFriend = 0; iFriend < unable; iFriend++)
{
int beaver; std::cin >> beaver;
notComing.emplace_back(beaver - 1);
busy[beaver - 1] = true;
}
if (unable < SQRT)
{
int far = 0;
while (far < (int)furthest[location].size() && busy[furthest[location][far].id])
far++;
if (far == (int)furthest[location].size())
std::cout << "-1\n";
else
std::cout << furthest[location][far].dist << '\n';
}
else
{
std::fill_n(seen, nodes, false);
std::cout << slowcheck(location) << '\n';
}
for (int beaver : notComing)
busy[beaver] = false;
}
return 0;
}
