#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
#define fi first
#define se second
#define vi vector<int>
#define vll vector<long long>
#define pii pair<int, int>
#define pll pair<long long, long long>
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
mt19937_64 rng64(chrono::high_resolution_clock::now().time_since_epoch().count());
inline int rand(int l,int r){return uniform_int_distribution<int>(l, r)(rng);}
inline ll rand(ll l,ll r){return uniform_int_distribution<ll>(l, r)(rng64);}
#ifdef DEBUG
auto&operator<<(auto&o,pair<auto,auto>p){return o<<"("<<p.first<<", "<<p.second<<")";}
auto operator<<(auto&o,auto x)->decltype(x.end(),o){o<<"{";int i=0;for(auto e:x)o<<","+!i++<<e;return o<<"}";}
#define debug(X...)cerr<<"["#X"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(X)
#else
#define debug(...){}
#endif
struct custom_hash {
static uint64_t splitmix64(uint64_t x) {
x += 0x9e3779b97f4a7c15;
x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
return x ^ (x >> 31);
}
size_t operator()(uint64_t x) const {
static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
return splitmix64(x + FIXED_RANDOM);
}
};
struct pair_hash{
size_t operator()(const pair<int,int>&x)const{
return hash<long long>()(((long long)x.first)^(((long long)x.second)<<32));
}
};
const int B = 467;
const int MAXN = 1e5 + 7;
const ll INF = 1e9 + 7;
const ll BIGINF = (ll)1e18;
vector<pll> vec[MAXN];
vector<pair<int, ll>> g[MAXN];
ll ans[MAXN];
vector<pii> queries[MAXN];
ll dist2[MAXN];
vi num[MAXN];
ll Dist[MAXN];
int info[MAXN];
int jump[MAXN];
ll odl[MAXN];
vll path[MAXN];
int n, q;
ll T;
int K = 1;
void Fix(int i){
sort(all(vec[i]));
ll mn = INF;
vector<pll> res = {};
for(int j = sz(vec[i]) - 1; j >= 0; j--){
if(vec[i][j].se < mn){
res.pb(vec[i][j]);
mn = vec[i][j].se;
}
}
reverse(all(res));
vec[i] = res;
}
void calcPre(int ind){
for(int j = 0; j < sz(vec[ind]); j++){
//policz skok
info[K] = ind;
num[ind].pb(K);
int l = 0;
int p = sz(vec[ind + 1]) - 1;
int mid;
while(l < p){
mid = (l + p) / 2;
if(vec[ind + 1][mid].fi >= vec[ind][j].se){
p = mid;
}else{
l = mid + 1;
}
}
if(vec[ind + 1][l].fi < vec[ind][j].se){
l = 0;
}
jump[K] = num[ind + 1][l];
odl[K] = vec[ind + 1][l].fi - vec[ind][j].fi;
if(vec[ind][j].se > vec[ind + 1][l].fi){
odl[K] += T;
}
g[jump[K]].pb(mp(K, odl[K]));
K++;
}
}
void dfs(int i, ll d){
Dist[info[i]] = min(Dist[info[i]], d);
for(auto [u, c] : g[i]){
dfs(u, (ll)c + d);
}
dist2[i] = d;
}
void solveBig(int ind){
for(int i = 1; i <= n; i++){
Dist[i] = BIGINF;
}
for(int i = 0; i < sz(vec[ind]); i++){
dfs(num[ind][i], vec[ind][i].se - vec[ind][i].fi);
}
for(auto [l, id] : queries[ind]){
ans[id] = Dist[l];
}
}
void addNew(int i){
for(int j = 0; j < sz(vec[i]); j++){
int e = num[i][j];
path[e].pb(dist2[e]);
for(auto [u, c] : g[e]){
path[u].pb(dist2[e]);
if(sz(path[e]) < sz(path[u])){
swap(path[e], path[u]);
}
for(int x = 0; x < sz(path[u]); x++){
path[e][sz(path[e]) - (sz(path[u]) - x)] = min(path[e][sz(path[e]) - (sz(path[u]) - x)], path[u][x]);
}
}
}
}
void solveSmall(int i){
for(auto [l, id] : queries[i]){
ans[id] = BIGINF;
for(int j = 0; j < sz(vec[i]); j++){
int ind = num[i][j];
if(sz(path[ind]) >= i - l + 1){
ans[id] = min(ans[id], vec[i][j].se - vec[i][j].fi - dist2[ind] + path[ind][sz(path[ind]) - (i - l + 1)]);
}
}
}
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(NULL);
cout.tie(NULL);
cin >> n >> T;
for(int i = 1; i < n; i++){
int M;
cin >> M;
for(int j = 1; j <= M; j++){
int a, b;
cin >> a >> b;
vec[i].pb(mp(a, b));
}
Fix(i);
}
cin >> q;
for(int i = 1; i <= q; i++){
int l, r;
cin >> l >> r;
r--;
queries[r].pb(mp(l, i));
}
for(int i = 0; i < sz(vec[n - 1]); i++){
info[K] = n - 1;
num[n - 1].pb(K);
g[0].pb(mp(K, 0LL));
K++;
}
for(int i = n - 2; i >= 1; i--){
calcPre(i);
}
for(int i = 1; i < n; i++){
if(sz(queries[i]) >= B){
solveBig(i);
}
}
dfs(0, 0LL);
for(int i = 1; i < n; i++){
addNew(i);
if(sz(queries[i]) < B){
solveSmall(i);
}
}
for(int i = 1; i <= q; i++){
cout << ans[i] << '\n';
}
return 0;
}
