#include <bits/stdc++.h>
using namespace std;
#define int long long
const int INF = 1e18;
int n,T,cntarb,q;
vector<pair<int,int>> v[100005];
vector<int> id[100005];
int base[100005];
int qle[300005], qri[300005], qrez[300005];
vector<pair<int,int>> qrys[100005];//{jumps, id}
vector<pair<int,int>> con[100005];
int sumr[100005], toroot[100005], depth[100005];
void dfs(int nod)
{
toroot[depth[nod]] = nod;
for(auto [jumps, qid]:qrys[nod])
{
assert(depth[nod] - jumps >= 0);
qrez[qid] = min(qrez[qid], base[nod] + sumr[nod] - sumr[toroot[depth[nod] - jumps]]);
}
for(auto [adj, w]:con[nod])
{
depth[adj] = depth[nod] + 1;
sumr[adj] = sumr[nod] + w;
dfs(adj);
}
}
signed main()
{
ios_base::sync_with_stdio(0);cin.tie(0);
cin>>n>>T;
for(int i=1;i<n;i++)
{
int nr;
cin>>nr;
v[i].resize(nr);
id[i].resize(nr);
for(int j=0;j<nr;j++)
cin>>v[i][j].first>>v[i][j].second;
sort(v[i].begin(), v[i].end());
for(int j=0;j<nr;j++)
{
id[i][j] = ++cntarb;
base[cntarb] = v[i][j].second - v[i][j].first;
}
}
/*for(int i=1;i<=n;i++)
{
cntarb++;
id[i].push_back(cntarb);
}*/
vector<pair<int,int>> tori(cntarb+2, {-1,-1}), tole(cntarb+2, {-1,-1});
for(int i=1;i+1<n;i++)
{
for(int j=0;j<v[i].size();j++)
{
int unde = -1, minb = T + 1;
for(int x=0;x<v[i+1].size();x++)
{
if(v[i+1][x].first >= v[i][j].second)
{
if(v[i+1][x].second < minb)
{
minb = v[i+1][x].second;
unde = id[i+1][x];
if(i == 1)
{
//cerr<<minb<<" "<<unde<<" zzz\n";
}
}
}
}
int cost = 0;
if(unde == -1)
{
assert(!v[i+1].empty());
unde = id[i+1][0];
cost = (T - v[i][j].second) + v[i+1][0].second;
}
else
{
cost = minb - v[i][j].second;
}
tori[id[i][j]] = {unde, cost};
}
}
cin>>q;
for(int i=1;i<=q;i++)
{
cin>>qle[i]>>qri[i];
qrez[i] = INF;
}
for(int i=1;i<=cntarb;i++)
{
if(tori[i].first == -1)
{
tori[i].first = cntarb + 1;
tori[i].second = 0;
}
con[tori[i].first].push_back({i, tori[i].second});
}
for(int i=1;i<=q;i++)
{
for(int j=0;j<v[qle[i]].size();j++)
{
qrys[id[qle[i]][j]].push_back({qri[i] - qle[i] - 1, i});
}
}
dfs(cntarb + 1);
for(int i=1;i<=cntarb+1;i++)
{
con[i].clear();
qrys[i].clear();
}
for(int i=1;i<=q;i++)
cout<<qrez[i]<<"\n";
return 0;
}
