#include <bits/stdc++.h>
using namespace std;
struct range {
int l, r;
};
const int MAX_N = 1e5;
const int MAX_LOG_N = 16;
const long long INF = 1e18;
int t;
vector<int> flightsByLoc[MAX_N + 1];
range flights[MAX_N + 1];
int nxt[MAX_LOG_N + 1][MAX_N + 1];
long long cost[MAX_LOG_N + 1][MAX_N + 1];
long long solve(int i, int k) {
long long ans = flights[i].r;
for (int p = MAX_LOG_N; p >= 0; p--) {
if (k >= (1 << p)) {
k -= (1 << p);
ans += (long long)t * cost[p][i];
i = nxt[p][i];
}
}
ans -= flights[i].l;
return ans;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int n, m = 0;
cin >> n >> t;
for (int i = 1; i <= n - 1; i++) {
int k;
cin >> k;
for (int j = 0; j < k; j++) {
int l, r;
cin >> l >> r;
flights[++m] = {l, r};
flightsByLoc[i].push_back(m);
}
sort(flightsByLoc[i].begin(), flightsByLoc[i].end(), [](int a, int b) {
return flights[a].r > flights[b].r;
});
}
for (int i = n - 1; i >= 2; i--) {
sort(flightsByLoc[i].begin(), flightsByLoc[i].end(), [](int a, int b) {
return flights[a].l < flights[b].l;
});
int bestGlobalL = -1, bestGlobalJ = 0;
for (int j: flightsByLoc[i - 1]) {
if (flights[j].l > bestGlobalL) {
bestGlobalL = flights[j].l;
bestGlobalJ = j;
}
}
int ind = flightsByLoc[i - 1].size();
int bestL = -1, bestJ = 0;
for (int j: flightsByLoc[i]) {
while (ind > 0 && flights[flightsByLoc[i - 1][ind - 1]].r <= flights[j].l) {
ind--;
if (flights[flightsByLoc[i - 1][ind]].l > bestL) {
bestL = flights[flightsByLoc[i - 1][ind]].l;
bestJ = flightsByLoc[i - 1][ind];
}
}
int l = (bestJ == 0 ? bestGlobalJ : bestJ);
nxt[0][j] = l;
}
}
for (int i = 1; i <= m; i++) {
if (nxt[0][i] == 0)
continue;
cost[0][i] = (flights[i].l >= flights[nxt[0][i]].r ? 0 : 1);
}
// for (int i = 1; i <= m; i++)
// printf("%d %d %lld\n", i, nxt[0][i], cost[0][i]);
for (int p = 1; (1 << p) <= m; p++) {
for (int i = 1; i <= m; i++) {
nxt[p][i] = nxt[p - 1][nxt[p - 1][i]];
cost[p][i] = cost[p - 1][i] + cost[p - 1][nxt[p - 1][i]];
}
}
int q;
cin >> q;
for (; q > 0; q--) {
int l, r;
cin >> l >> r;
int cnt = 0;
long long best = INF;
for (int j: flightsByLoc[r - 1]) {
best = min(best, solve(j, r - l - 1));
cnt++;
}
cout << best << "\n";
}
return 0;
}
