#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N=100010, L=17, B=100, INF=1e18;
int n, t, q, rt[N];
vector<int> nxt[L][N], sum[L][N], dist[N], dist2[N];
vector<pair<int, int>> v[N];
pair<int, int> f(int l, int r, int k) {
int x=r-l, p=l;
pair<int, int> ret={k, 0};
for(int i=31-__builtin_clz(x); i>=0; i--) if(x&(1<<i)) {
ret.second+=sum[i][p][ret.first], ret.first=nxt[i][p][ret.first];
p+=(1<<i);
}
return ret;
}
int g(int l, int r, int k) {
if(l>=r) return 0;
pair<int, int> tmp=f(l, r-1, k);
return tmp.second+v[r-1][tmp.first].second-v[r-1][tmp.first].first;
}
signed main() {
ios_base::sync_with_stdio(0); cin.tie(0);
cin>>n>>t;
for(int i=1; i<n; i++) {
int m; cin>>m;
while(m--) {
int a, b; cin>>a>>b;
v[i].push_back({a, b});
}
}
v[n].push_back({0, 0});
for(int i=1; i<=n; i++) {
vector<pair<int, int>> tmp;
sort(v[i].begin(), v[i].end());
for(int j=0; j<v[i].size(); j++) {
while(!tmp.empty() && tmp.back().second>=v[i][j].second) tmp.pop_back();
tmp.push_back(v[i][j]);
}
v[i]=tmp;
for(int j=0; j<L; j++) nxt[j][i].resize(v[i].size()), sum[j][i].resize(v[i].size());
}
for(int i=1; i<=n-1; i++) for(int j=0; j<v[i].size(); j++) {
if(v[i][j].second>v[i+1].back().first) {
nxt[0][i][j]=0, sum[0][i][j]=t+v[i+1][0].first-v[i][j].first;
}
else {
nxt[0][i][j]=lower_bound(v[i+1].begin(), v[i+1].end(), make_pair(v[i][j].second, 0ll))-v[i+1].begin();
sum[0][i][j]=v[i+1][nxt[0][i][j]].first-v[i][j].first;
}
}
for(int k=1; k<L; k++) for(int i=1; i<n; i++) for(int j=0; j<v[i].size(); j++) if(i+(1<<k)-1<=n) {
nxt[k][i][j]=nxt[k-1][i+(1<<(k-1))][nxt[k-1][i][j]];
sum[k][i][j]=sum[k-1][i][j]+sum[k-1][i+(1<<(k-1))][nxt[k-1][i][j]];
}
for(int i=n-1, p=0; i>=1; i--) {
if(v[i].size()<=B) p=i;
else if(p) {
rt[i]=p;
dist[i].resize(v[p].size(), INF);
for(int j=0; j<v[i].size(); j++) {
pair<int, int> tmp=f(i, p, j);
dist[i][tmp.first]=min(dist[i][tmp.first], tmp.second);
}
}
else rt[i]=n+1;
}
for(int i=1; i<n; i++) if(v[i].size()>=B) {
vector<pair<int, int>> tmp;
for(int j=0; j<v[i].size(); j++) tmp.push_back({j, 0});
for(int j=i+1; j<=n; j++) {
if(v[j].size()<B) break;
int mn=INF;
for(int k=0; k<v[i].size(); k++) mn=min(mn, tmp[k].second+v[j-1][tmp[k].first].second-v[j-1][tmp[k].first].first);
dist2[i].push_back(mn);
if(j==n) break;
for(int k=0; k<v[i].size(); k++) {
tmp[k].second+=sum[0][j-1][tmp[k].first], tmp[k].first=nxt[0][j-1][tmp[k].first];
}
}
}
cin>>q;
while(q--) {
int l, r; cin>>l>>r;
int ret=INF;
if(v[l].size()<=B) {
for(int i=0; i<v[l].size(); i++) ret=min(ret, g(l, r, i));
cout<<ret<<"\n"; continue;
}
if(rt[l]<=r) {
int p=rt[l];
for(int i=0; i<v[p].size(); i++) ret=min(ret, g(p, r, i)+dist[l][i]);
cout<<ret<<"\n"; continue;
}
if(dist2[l].size()<r-l-1) return 0;
cout<<dist2[l][r-l-1]<<"\n";
}
return 0;
}
