#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define re exit(0);
#define thuhien ""
const int LOG = 17;
int n,t;
vector <pair <int,int>> flight[100009];
vector <int> position[100009];
int cnt;
pair <int,int> plane[100009];
ll up[100009][LOG + 1];
int belong[100009];
ll nextday(ll day) {
return 1ll*(day/t + 1)*t;
}
bool intersect(pair <int,int> a,pair <int,int> b) {
if (a.first > b.first) swap(a,b);
return !(a.first < b.first && a.second < b.second);
}
ll move(int l,int r,int currflight,int LOG) {
ll res = 0;
for (;;LOG--) if (l + (1 << LOG) - 1 <= r) break;
int next = l + (1 << LOG) - 1;
if (next == r) {
return up[currflight][LOG];
}
res = up[currflight][LOG];
int nextflight = lower_bound(flight[next].begin(),flight[next].end(),make_pair((int)(res % t),-1)) - flight[next].begin();
if (nextflight != flight[next].size()) return res - res % t + move(next,r,position[next][nextflight],LOG);
return nextday(res) + move(next,r,position[next][0],LOG);
}
void solve() {
int l,r;cin >> l >> r;
int currflight = position[l][0];
cout << move(l,r,currflight,LOG) - flight[l][0].first << '\n';
}
int main() {
ios_base::sync_with_stdio(0);cin.tie(nullptr);
if (fopen(thuhien".inp","r")) {
freopen(thuhien".inp","r",stdin);
freopen(thuhien".out","w",stdout);
}
cin >> n >> t;
for (int i = 1;i < n;i++) {
int num;cin >> num;
for (int j = 1;j <= num;j++) {
pair <int,int> a;cin >> a.first >> a.second;
flight[i].push_back(a);
}
// Gi? s? flight[i] ban d?u là vector<pair<int,int>> {depart, arrive} cho city i
auto &v = flight[i];
// 1) Sort theo depart asc, arrive asc
sort(v.begin(), v.end());
// 2) G?p cùng depart, gi? arrival nh? nh?t
vector<pair<int,int>> w;
w.reserve(v.size());
for (size_t p = 0; p < v.size(); ) {
size_t q = p;
int mind = v[p].second;
while (q < v.size() && v[q].first == v[p].first) {
mind = min(mind, v[q].second);
++q;
}
w.push_back({v[p].first, mind});
p = q;
}
// 3) Suffix-min prune (gi? nh?ng chuy?n làm gi?m arrival khi di ngu?c)
vector<pair<int,int>> opt;
opt.reserve(w.size());
int best = INT_MAX;
for (int k = (int)w.size() - 1; k >= 0; --k) {
if (w[k].second >= best) continue; // b? th?ng tr? b?i suffix
best = w[k].second;
opt.push_back(w[k]);
}
reverse(opt.begin(), opt.end());
// K?t qu? cu?i cùng
flight[i].swap(opt);
// (Sau dó fill position[i] nhu tru?c)
for (auto x : flight[i]) {
++cnt;
plane[cnt] = x;
belong[cnt] = i;
position[i].push_back(cnt);
}
}
// for (int i = 1;i < n;i++) {
// cout << "CITY: " << i << '\n';
// for (auto x : position[i]) cout << x << '\n';
// }
//di tu i -> i + 1 mat min la bn
for (int i = 1;i <= cnt;i++) {
up[i][1] = plane[i].second;
}
for (int j = 2;j <= LOG;j++) {
for (int i = 1;i <= cnt && belong[i] + (1 << j) - 1 <= n;i++) {
int mid = belong[i] + (1 << (j - 1)) - 1,r = mid + 1;
//mid -> r
ll nexttime = up[i][j - 1];
int nextflight = lower_bound(flight[mid].begin(),flight[mid].end(),make_pair((int)(nexttime % t),-1)) - flight[mid].begin();
if (nextflight != flight[mid].size()) nexttime = nexttime - nexttime % t + flight[mid][nextflight].second;
else nexttime = nextday(nexttime) + flight[mid][0].second;
//xem bat chuyen nao cua r
nextflight = lower_bound(flight[r].begin(),flight[r].end(),make_pair((int)(nexttime % t),-1)) - flight[r].begin();
if (nextflight != flight[r].size()) up[i][j] = nexttime - nexttime % t + up[ position[r][nextflight] ][j - 1];
else up[i][j] = nextday(nexttime) + up[ position[r][0] ][j - 1];
}
}
int q;cin >> q;while (q--) solve();
}
