#include <bits/stdc++.h>
using namespace std;
using ll =long long;
#define F0R(i, n) for (ll i = 0; i < n;i++)
#define FOR(i,j,n) for(ll i = j;i < n;i++)
template<typename T>
using V = vector<T>;
using vi = V<ll>;
using pi = pair<ll, ll>;
#define all(x) x.begin(), x.end()
#define f first
#define s second
constexpr ll INF = 1e18;
using tup = tuple<ll, ll, ll>;
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;
}
ll T;
V<pair<pi, ll>> create(V<pi> x) {
V<pair<pi, ll>> ans(x.size());
for (ll i = 0; i < x.size(); ++i) {
ans[i] = {x[i], 0};
}
return ans;
}
V<pair<pi, ll>> next(const V<pair<pi, ll>> ¤t, ll i, V<pi> &next, bool sign) {
V<pair<pi, ll>> results;
for (auto [dat, c] : current) {
auto [a,b] = dat;
auto it = std::lower_bound(next.begin(), next.end(), make_pair(b, -INF));
if (it != next.end())
results.emplace_back(make_pair(a, it->second), c);
else if (!next.empty()){
it = next.begin();
results.emplace_back(make_pair(a, it->second), c + 1);
}
}
return results;
}
// Must jump over all l and r
void solve(ll l, ll r, V<tuple<ll,ll,ll>> queries) {
ll mid = (r + l) / 2;
if (r - l <= 1) {
V<pair<pi, ll>> times = create(in[l]);
for (auto [a,b, i] : queries) {
ll res = INF;
for (auto [dat, r] : times) {
auto [x,y] = dat;
res = min(res, y - x);
}
ans[i] = res;
}
return;
}
V<tuple<ll,ll,ll>> 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<pair<pi, ll>> times = create(in[mid]);
V<V<pair<pi, ll>>> to, from;
FOR(i, mid + 1, r) {
to.emplace_back(times);
times = next(times,i, in[i], false);
}
to.emplace_back(times);
times = create(out[mid]);
for (auto &[aData,r] : times) {
auto &[a,b] = aData;
a = -b;
}
for (ll i = mid - 1; i >= l;i--) {
from.emplace_back(times);
times = next(times, i, out[i], true);
}
from.emplace_back(times);
for (auto [a,b, i] : currentQueries) {
if (i == 0) {
int stop = 25;
}
V<pair<pi, ll>> end = to[b - mid - 1];
V<pair<pi, ll>> start = from[mid - a];
ll bestTime = INF;
for (auto [dat,c] : start) {
auto [x,y] = dat;
swap(x,y);
x *= -1;
for (auto [dat2, c2] : end) {
auto [x2,y2] = dat2;
if (y <= x2) bestTime = min(bestTime, y2 - x + (c + c2) * T);
}
}
ans[i] = bestTime;
}
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(nullptr);
ll n; cin >> n >> T;
in.resize(n), out.resize(n);
F0R(i, n - 1) {
ll m; cin >> m;
F0R(j, m) {
ll a, b; cin >> a >> b;
in[i].emplace_back(a,b);
}
sort(all(in[i]));
in[i] = fix(in[i]);
for (auto [a,b] : in[i]) {
out[i].emplace_back(b,a);
}
F0R(j, out[i].size()) {
out[i][j].f *= -1; // Switch signs
out[i][j].s *= -1; // Switch signs
}
sort(all(out[i]));
}
V<tuple<ll,ll,ll>> queries;
ll q; cin >> q;
ans.resize(q);
F0R(i, q) {
ll 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;
}
