#include <bits/stdc++.h>
#define pii pair<int,int>
#define ff first
#define ss second
using namespace std;
int const BLOCKSIZE=43;
long long const INF=1e18;
int const MAX=100005;
int const LOG=20;
int n,t;
int nrd[MAX];
vector<pii>drum[MAX];
int ln[MAX],rn[MAX];
int tata[MAX];
long long spn[MAX],spm[MAX];
vector<int>sons[MAX];
int lift[MAX][LOG];
vector<long long>dist[MAX];
long long dp[MAX];
void read(){
cin>>n>>t;
int i,j;
for(i=1;i<n;++i){
cin>>nrd[i];
ln[i]=rn[i-1]+1;
rn[i]=ln[i]+nrd[i]-1;
for(j=0;j<nrd[i];++j){
int a,b;
cin>>a>>b;
drum[i].push_back({a,b});
}
sort(drum[i].begin(),drum[i].end());
}
}
void create_forest(){
int i,j;
for(i=1;i<=n-2;++i){
vector<int>best;
best.resize(nrd[i+1]);
best[nrd[i+1]-1]=nrd[i+1]-1;
for(j=nrd[i+1]-2;j>=0;--j)
if(drum[i+1][j].ss<drum[i+1][best[j+1]].ss)
best[j]=j;
else
best[j]=best[j+1];
for(j=0;j<nrd[i];++j){
auto it=lower_bound(drum[i+1].begin(),drum[i+1].end(),make_pair(drum[i][j].ss,0));
if(it==drum[i+1].end()){
tata[ln[i]+j]=ln[i+1]+best[0];
sons[ln[i+1]+best[0]].push_back(ln[i]+j);
spm[ln[i]+j]=t-drum[i][j].ss+drum[i+1][best[0]].ff;
}
else{
int id=it-drum[i+1].begin();
tata[ln[i]+j]=ln[i+1]+best[id];
sons[ln[i+1]+best[id]].push_back(ln[i]+j);
spm[ln[i]+j]=drum[i+1][best[id]].ff-drum[i][j].ss;
}
}
}
for(i=1;i<n;++i)
for(j=0;j<nrd[i];++j)
spn[ln[i]+j]=drum[i][j].ss-drum[i][j].ff;
}
void dfs(int nod){
spm[nod]+=spn[tata[nod]];
spn[nod]+=spm[nod];
int i;
lift[nod][0]=tata[nod];
for(i=1;i<LOG;++i)
lift[nod][i]=lift[lift[nod][i-1]][i-1];
for(auto fiu : sons[nod])
dfs(fiu);
}
void dfs_driver(){
int i;
for(i=ln[n-1];i<=rn[n-1];++i)
dfs(i);
}
int anc(int nod,int h){
int i;
for(i=0;i<LOG;++i)
if(h&(1<<i))
nod=lift[nod][i];
return nod;
}
void minself(long long& x,long long val){
if(x>val)
x=val;
}
long long solve(int st,int dest){
long long ans=INF;
int h=dest-st-1;
int i;
for(i=ln[st];i<=rn[st];++i){
int stramos=anc(i,h);
minself(ans,spn[i]-spm[stramos]);
}
return ans;
}
void dfs_init(int nod,int niv,int target){
if(niv==target)
dp[nod]=spn[nod];
else{
dp[nod]=INF;
for(auto fiu : sons[nod]){
dfs_init(fiu,niv-1,target);
minself(dp[nod],dp[fiu]);
}
}
minself(dist[target][niv+1],dp[nod]-spm[nod]);
}
void dfs_init_driver(){
int i,j;
for(i=1;i<n;++i)
if(nrd[i]>BLOCKSIZE){
dist[i].resize(n+5,INF);
for(j=ln[n-1];j<=rn[n-1];++j)
dfs_init(j,n-1,i);
}
}
void process_queries(){
int i;
int q;
cin>>q;
for(i=1;i<=q;++i){
int st,dest;
cin>>st>>dest;
if(nrd[st]<=BLOCKSIZE)
cout<<solve(st,dest)<<'\n';
else
cout<<dist[st][dest]<<'\n';
}
}
int main()
{
read();
create_forest();
dfs_driver();
dfs_init_driver();
process_queries();
return 0;
}
