#include <bits/stdc++.h>
using namespace std;
#define F0R(i, n) for (int i = 0; i < n;i++)
#define FOR(i,j,n) for(int i = j;i < n;i++)
template<typename T>
using V = vector<T>;
using vi = V<int>;
using pi = pair<int, int>;
#define all(x) x.begin(), x.end()
#define f first
#define s second
constexpr int INF = 1e9;
vi ans;
V<V<pi>> in, out;
V<pi> fix(V<pi> arr) {
V<pi> fixed;
F0R(i, arr.size()) {
while (!fixed.empty() and fixed.back().s > arr[i].s) fixed.pop_back();
fixed.push_back(arr[i]);
}
return fixed;
}
int T;
int sign(int x) {
if (x >= 0) return 1;
return -1;
}
V<pi> next(const V<pi> ¤t, int i, V<pi> &in) {
V<pi> results;
for (auto [a, b] : current) {
auto it = std::lower_bound(in.begin(), in.end(), make_pair(b % T,-INF));
if (it != in.end())
results.emplace_back(a, it->second);
else if (!in.empty()){
it = in.begin();
results.emplace_back(a, it->second + T);
}
}
return results;
}
// Must jump over all l and r
void solve(int l, int r, V<tuple<int,int,int>> queries) {
int mid = (r + l) / 2;
if (r - l <= 1) return;
V<tuple<int,int,int>> leftQueries, rightQueries, currentQueries;
for (auto [a, b, i] : queries) {
if (b <= mid) leftQueries.emplace_back(a,b,i);
else if (a >= mid) rightQueries.emplace_back(a, b, i);
else currentQueries.emplace_back(a, b, i);
}
solve(l, mid, leftQueries);
solve(mid, r, rightQueries);
V<pi> times = in[mid];
V<V<pi>> to, from;
FOR(i, mid + 1, r) {
to.emplace_back(times);
times = next(times,i, in[i]);
}
to.emplace_back(times);
times = out[mid];
for (auto &[a,b] : times) a = -b;
for (int i = mid - 1; i >= l;i--) {
from.emplace_back(times);
times = next(times, i, out[i]);
}
from.emplace_back(times);
map<int, int> inId, outId;
int iter = 0;
for (auto [a,b] : in[mid]) {
inId[a] = iter++;
}
iter = 0;
for (auto [b, a] : out[mid]) {
outId[b] = iter++;
}
for (auto [a,b, i] : currentQueries) {
V<pi> end = to[b - mid - 1];
V<pi> start = from[mid - a];
int bestTime = 1e9;
for (auto [x,y] : start) {
swap(x,y);
x *= -1;
for (auto [x2, y2] : end) {
if (y <= x2) bestTime = min(bestTime, y2 - x);
}
}
ans[i] = bestTime;
}
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(nullptr);
int n; cin >> n >> T;
in.resize(n), out.resize(n);
F0R(i, n - 1) {
int m; cin >> m;
F0R(j, m) {
int a, b; cin >> a >> b;
in[i].emplace_back(a,b);
out[i].emplace_back(b, a);
}
sort(all(in[i]));
sort(all(out[i]));
out[i] = fix(out[i]);
F0R(j, m) out[i][j].f *= -1; // Switch signs
F0R(j, m) out[i][j].s *= -1; // Switch signs
sort(all(out[i]));
in[i] = fix(in[i]);
}
V<tuple<int,int,int>> queries;
int q; cin >> q;
ans.resize(q);
F0R(i, q) {
int l, r; cin >> l >> r;
l--;
r--;
queries.emplace_back(l, r, i);
}
solve(0, n, queries);
F0R(i, q) {
cout << ans[i] << "\n";
}
return 0;
}
