#include <iostream>
#include <bits/stdc++.h>
#define ll long long
using namespace std;
const ll maxn = 2*1e5+5, INF = 4e18+9;
struct normalize{
vector<ll> poi, pot;
void add(ll x){
poi.push_back(x);
}
void start(){
sort(poi.begin(), poi.end());
if(poi.size() > 0) pot.push_back(poi[0]);
for(int i = 1; i < (int)poi.size(); i++){
if(poi[i] != poi[i-1]){
pot.push_back(poi[i]);
}
}
}
int encode(ll x){
return lower_bound(pot.begin(), pot.end(), x) - pot.begin()+1;
}
};
// supports: point modify, range apply, range query, walk to find first/last with some precedent
// you are to implement the 2 structs Tag and Info
// for the walks, pass a lambda that takes in Info and return true iff the node with that Info will contain the desired element
template<class Info, class Tag>
struct LazySegmentTree {
int n;
vector<Info> info;
vector<Tag> tag;
LazySegmentTree() : n(0) {}
LazySegmentTree(int n_, Info v_ = Info()) {
init(n_, v_);
}
template<class T>
LazySegmentTree(vector<T> init_) {
init(init_);
}
void init(int n_, Info v_ = Info()) {
init(vector<Info>(n_, v_));
}
template<class T>
void init(vector<T> init_) {
n = init_.size();
info.assign(4 << __lg(n), Info());
tag.assign(4 << __lg(n), Tag());
function<void(int, int, int)> build = [&](int p, int l, int r) {
if (r - l == 1) {
info[p] = init_[l];
return;
}
int m = (l + r) / 2;
build(2 * p, l, m);
build(2 * p + 1, m, r);
pull(p);
};
build(1, 0, n);
}
void pull(int p) {
info[p] = info[2 * p] + info[2 * p + 1];
}
void apply(int p, const Tag &v) {
info[p].apply(v);
tag[p].apply(v);
}
void push(int p) {
apply(2 * p, tag[p]);
apply(2 * p + 1, tag[p]);
tag[p] = Tag();
}
void modify(int p, int l, int r, int x, const Info &v) {
if (r - l == 1) {
info[p] = v;
return;
}
int m = (l + r) / 2;
push(p);
if (x < m) {
modify(2 * p, l, m, x, v);
} else {
modify(2 * p + 1, m, r, x, v);
}
pull(p);
}
void modify(int p, const Info &v) {
modify(1, 0, n, p, v);
}
Info rangeQuery(int p, int l, int r, int x, int y) {
if (l >= y || r <= x) {
return Info();
}
if (l >= x && r <= y) {
return info[p];
}
int m = (l + r) / 2;
push(p);
return rangeQuery(2 * p, l, m, x, y) + rangeQuery(2 * p + 1, m, r, x, y);
}
Info rangeQuery(int l, int r) {
return rangeQuery(1, 0, n, l, r);
}
void rangeApply(int p, int l, int r, int x, int y, const Tag &v) {
if (l >= y || r <= x) {
return;
}
if (l >= x && r <= y) {
apply(p, v);
return;
}
int m = (l + r) / 2;
push(p);
rangeApply(2 * p, l, m, x, y, v);
rangeApply(2 * p + 1, m, r, x, y, v);
pull(p);
}
void rangeApply(int l, int r, const Tag &v) {
return rangeApply(1, 0, n, l, r, v);
}
template<class F>
int findFirst(int p, int l, int r, int x, int y, F &&pred) {
if (l >= y || r <= x) {
return -1;
}
if (l >= x && r <= y && !pred(info[p])) {
return -1;
}
if (r - l == 1) {
return l;
}
int m = (l + r) / 2;
push(p);
int res = findFirst(2 * p, l, m, x, y, pred);
if (res == -1) {
res = findFirst(2 * p + 1, m, r, x, y, pred);
}
return res;
}
template<class F>
int findFirst(int l, int r, F &&pred) {
return findFirst(1, 0, n, l, r, pred);
}
template<class F>
int findLast(int p, int l, int r, int x, int y, F &&pred) {
if (l >= y || r <= x) {
return -1;
}
if (l >= x && r <= y && !pred(info[p])) {
return -1;
}
if (r - l == 1) {
return l;
}
int m = (l + r) / 2;
push(p);
int res = findLast(2 * p + 1, m, r, x, y, pred);
if (res == -1) {
res = findLast(2 * p, l, m, x, y, pred);
}
return res;
}
template<class F>
int findLast(int l, int r, F &&pred) {
return findLast(1, 0, n, l, r, pred);
}
};
struct Tag {
void apply(const Tag &t) & {
}
};
struct Info {
int mn = 1e9, id = -1;
void apply(const Tag &t) & {
}
Info operator+(const Info &b) {
Info a = *this;
if(a.mn < b.mn) return a;
return b;
}
};
void solve(){
int n, L;
cin >> n >> L;
vector<int> M(n+1);
vector<vector<int>> a(n+1), b(n+1);
for(int i = 1; i < n; i++){
cin >> M[i];
a[i].resize(M[i]+1);
b[i].resize(M[i]+1);
for(int j = 1; j <= M[i]; j++){
cin >> a[i][j] >> b[i][j];
}
}
M[n] = 1;
//build the goddamn tree
int N = 0;
vector<vector<int>> tn(n+1);
for(int i = 1; i <= n; i++){
if(i == 1){
tn[i].resize(M[i]+1);
for(int j = 1; j <= M[i]; j++){
N++;
tn[i][j] = N;
}
}else if(i < n){
tn[i].resize(M[i-1]+M[i]+1);
for(int j = 1; j <= M[i-1]; j++){
N++;
tn[i][j] = N;
}
for(int j = 1; j <= M[i]; j++){
N++;
tn[i][j+M[i-1]] = N;
}
}else{
tn[i].resize(M[i-1]+1);
for(int j = 1; j <= M[i-1]; j++){
N++;
tn[i][j] = N;
}
}
}
vector<vector<pair<ll, ll>>> adj(N+1);
vector<pair<ll, ll>> pa(N+1);
auto add_edge = [&](int u, int v, int w) -> void{
adj[u].push_back({v, w});
pa[v] = {u, w};
//cout << u << " " << v << " " << w << "\n";
};
LazySegmentTree<Info, Tag> T(N+1);
vector<int> sz(n+1);
for(int i = 1; i <= n; i++){
if(i == 1){
for(int j = 1; j <= M[i]; j++){
int u = tn[i+1][j];
int v = tn[i][j];
int w = b[i][j] - a[i][j];
add_edge(u, v, w);
}
sz[i] = M[i];
}else if(i < n){
normalize norm;
for(int j = 1; j <= M[i-1]; j++){
norm.add(b[i-1][j]);
}
for(int j = 1; j <= M[i]; j++){
norm.add(a[i][j]);
}
norm.start();
for(int j = 1; j <= M[i]; j++){
int u = tn[i+1][j];
int v = tn[i][j+M[i-1]];
int w = b[i][j] - a[i][j];
add_edge(u, v, w);
}
for(int j = 1; j <= M[i]; j++){
T.modify(norm.encode(a[i][j]), {b[i][j], j});
}
for(int j = 1; j <= M[i-1]; j++){
int p = T.rangeQuery(norm.encode(b[i-1][j]), N+1).id;
ll w;
if(p == -1){
p = T.rangeQuery(1, N+1).id;
w = b[i][p] + L - b[i-1][j];
}else{
w = b[i][p] - b[i-1][j];
}
int u = tn[i+1][p];
int v = tn[i][j];
add_edge(u, v, w);
}
//reset DS
for(int j = 1; j <= M[i]; j++){
T.modify(norm.encode(a[i][j]), Info());
}
sz[i] = M[i-1] + M[i];
}else{
for(int j = 1; j <= M[i-1]; j++){
int u = tn[i][j];
add_edge(0, u, 0);
}
sz[i] = M[i-1];
}
}
auto chmin = [&](ll &a, ll b) -> void{
a = min(a, b);
};
int B = 500;
vector<vector<ll>> big(n+1);
for(int i = 1; i <= n; i++){
if(sz[i] > B){
//3 for loops but O(n) trust me bro
//constant factor is (?)
big[i].resize(n+1, INF);
big[i][i] = 0;
vector<ll> d(N+1, INF);
for(int it = 1; it <= sz[i]; it++){
int u = tn[i][it];
d[u] = 0;
}
for(int j = i+1; j <= n; j++){
for(int it = 1; it <= sz[j]; it++){
int u = tn[j][it];
for(auto e : adj[u]){
ll v = e.first, w = e.second;
chmin(d[u], d[v]+w);
chmin(big[i][j], d[u]);
}
}
}
}
}
int Q;
cin >> Q;
vector<ll> ans(Q+1, INF);
vector<vector<pair<int ,int>>> q(n+1);
for(int i = 1; i <= Q; i++){
int l, r;
cin >> l >> r;
if(sz[l] > B){
ans[i] = big[l][r];
continue;
}
q[n+1 - l].push_back({n+1 - r, i});
}
vector<ll> d(N+1, 0);
vector<int> st;
auto dfs = [&](auto dfs, int u, int len) -> void{
for(auto it : q[len]){
int p = it.first, id = it.second;
chmin(ans[id], d[u] - d[st[p]]);
}
st.push_back(u);
for(auto it : adj[u]){
ll v = it.first, w = it.second;
d[v] = d[u] + w;
dfs(dfs, v, len+1);
}
st.pop_back();
};
dfs(dfs, 0, 0);
for(int i = 1; i <= Q; i++){
cout << ans[i] << "\n";
}
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
solve();
}
