#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pl;
typedef pair<int,int> pii;
typedef tuple<int,int,int> tpl;
#define all(a) a.begin(), a.end()
#define filter(a) a.erase(unique(all(a)), a.end())
const int mn = 1e5 + 5, Q = 3e5 + 5;
//const int limFlight = 10, limQuery = 10;
const int limFlight = 316, limQuery = 1000;
vector<pl> flight[mn], nxt[18][mn], qry[mn];
vector<ll> save[mn];
ll best[mn], ans[Q], n, T;
void refine (vector<pl> &vec) {
priority_queue<pl> pq;
sort(all(vec), [&] (pl a, pl b)
{ return (a.first == b.first ? a.second > b.second : a.first < b.first); });
for (pl item : vec) {
ll a, b; tie(a, b) = item;
while (pq.size() && pq.top().first >= b) pq.pop();
pq.emplace(b, a);
}
vec.clear();
while (pq.size()) {
ll a, b; tie(b, a) = pq.top(); pq.pop();
vec.emplace_back(a, b);
}
reverse(all(vec));
}
ll quickJump (int u, int flightID, int step) {
ll ans = 0;
for (int i = 0; step; step >>= 1, i++) {
if ((step & 1) == 0) continue;
ll weight; tie(flightID, weight) = nxt[i][u][flightID];
u += (1 << i), ans += weight;
}
return ans;
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
/// read flights info
cin >> n >> T;
for (int i = 1; i < n; i++) {
int m; cin >> m;
flight[i].resize(m);
for (pl &it : flight[i])
cin >> it.first >> it.second;
refine(flight[i]);
assert(flight[i].size());
}
for (int s = 0; s < 18; s++)
for (int i = 1; i < n; i++) nxt[s][i].resize(flight[i].size());
/// construct edges + bin-lift pre-compute
for (int i = 1; i + 1 < n; i++) {
int iter = 0;
for (int j = 0; j < flight[i].size(); j++) {
while (iter < flight[i + 1].size() && flight[i][j].second > flight[i + 1][iter].first) iter++;
if (iter < flight[i + 1].size())
nxt[0][i][j] = {iter, flight[i + 1][iter].second - flight[i][j].second};
else nxt[0][i][j] = {0, flight[i + 1][0].second + T - flight[i][j].second};
// cout << "(" << i << ", " << j << ") -> (" << i + 1 << ", " << nxt[0][i][j].first << "), weight " << nxt[0][i][j].second << "\n";
}
}
for (int s = 1; s < 18; s++) {
for (int i = 1; i + (1 << s) < n; i++) {
for (int j = 0; j < flight[i].size(); j++) {
ll id, weight; tie(id, weight) = nxt[s - 1][i][j];
ll nxtID, nxtWeight; tie(nxtID, nxtWeight) = nxt[s - 1][i + (1 << (s - 1))][id];
nxt[s][i][j] = {nxtID, weight + nxtWeight};
}
}
}
/// read queries
int q; cin >> q;
for (int i = 0; i < q; i++) {
int l, r; cin >> l >> r;
qry[l].emplace_back(r, i);
}
/// process queries
for (int i = 1; i < n; i++) {
if (qry[i].empty()) continue;
if (flight[i].size() > limFlight || qry[i].size() > limQuery) { // calculate for every possible R
for (int j = i; j < n; j++) save[j] = vector<ll>(flight[j].size(), LLONG_MAX);
for (int k = 0; k < flight[i].size(); k++)
save[i][k] = flight[i][k].second - flight[i][k].first;
for (int j = i; j + 1 < n; j++) {
for (int k = 0; k < flight[j].size(); k++) {
if (save[j][k] == LLONG_MAX) continue;
ll nxtID, weight; tie(nxtID, weight) = nxt[0][j][k];
save[j + 1][nxtID] = min(save[j + 1][nxtID], save[j][k] + weight);
}
}
for (int j = i; j < n; j++) best[j] = *min_element(all(save[j]));
for (pii item : qry[i]) {
int r, idx; tie(r, idx) = item;
ans[idx] = best[r - 1];
}
}
else { // simply brute-force
for (pii item : qry[i]) {
int r, idx; tie(r, idx) = item;
ans[idx] = LLONG_MAX;
for (int k = 0; k < flight[i].size(); k++)
ans[idx] = min(ans[idx], quickJump(i, k, r - i - 1) + flight[i][k].second - flight[i][k].first);
}
}
}
for (int i = 0; i < q; i++) cout << ans[i] << "\n";
return 0;
}
