#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define pb push_back
#define ff first
#define ss second
const ll inf = numeric_limits<ll> :: max();
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n, D; cin>>n>>D;
vector<int> x(n);
vector<pii> t[n];
for (int i = 1; i < n; i++){
cin>>x[i];
for (int j = 0; j < x[i]; j++){
int a, b; cin>>a>>b;
t[i].pb({a, b});
}
}
for (int i = 1; i < n; i++){
sort(t[i].begin(), t[i].end());
vector<pii> nw;
for (int j = 0; j < x[i]; j++){
while (!nw.empty() && nw.back().ss >= t[i][j].ss){
nw.pop_back();
}
if (nw.empty() || nw.back().ff != t[i][j].ff){
nw.pb(t[i][j]);
}
}
t[i] = nw;
x[i] = (int) t[i].size();
}
vector<int> p(n);
for (int i = 1; i < n; i++){
p[i] = p[i - 1] + x[i];
}
int S = p.back();
vector<int> g(S);
vector<bool> e(S);
for (int i = 1; i + 1 < n; i++){
int k = x[i + 1] - 1, mn = 0;
for (int j = x[i] - 1; j >= 0; j--){
while (k >= 0 && t[i + 1][k].ff >= t[i][j].ss){
mn = k--;
}
g[p[i - 1] + j] = p[i] + mn;
e[p[i - 1] + j] = (t[i][j].ss > t[i + 1][mn].ff);
}
}
auto get = [&](int l, int r){
ll out = inf;
for (int i = 0; i < x[l]; i++){
int tt = r - l - 1, f = p[l - 1] + i, cc = 0;
while (tt--){
cc += e[f];
f = g[f];
}
out = min(out, 1LL * D * cc + (t[r - 1][f - p[r - 2]].ss - t[l][i].ff));
}
return out;
};
int q; cin>>q;
for (int i = 1; i <= q; i++){
int l, r; cin>>l>>r;
cout<<get(l, r)<<"\n";
}
}
