#ifndef LOCAL
#pragma GCC Optimize("O3,Ofast,unroll-loops")
#pragma GCC Target("bmi,bmi2,avx,avx2")
#endif
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
#define int ll
#define f first
#define s second
#define mp make_pair
#define pb push_back
#define pii pair<int, int>
#define all(x) (x).begin(), (x).end()
#ifndef LOCAL
#define endl "\n"
#endif
#define TT template <typename T>
mt19937 rnd(11);
TT
istream& operator>>(istream &in,vector<T>&v){for(auto &x:v)in>>x;return in;}
TT
ostream& operator<<(ostream &out,vector<T>&v){for(auto &x:v)out<<x<<' ';return out;}
TT
istream& operator>>(istream &in,pair<T,T>&p){in>>p.f>>p.s;return in;}
const int LOG_N = 17;
void solve() {
int n, t;
cin >> n >> t;
vector<vector<array<int, 3>>> e(n), re(n);
vector<array<int, 3>> indexes;
int ind = 0;
for (int i = 0; i < n - 1; ++i) {
int m;
cin >> m;
e[i].resize(m);
int num = 0;
for (auto &x : e[i]) {
cin >> x[0] >> x[1];
indexes.pb({i, x[0], x[1]});
x[2] = ind++;
}
}
for (int i = 0; i < n; ++i) {
sort(all(e[i]));
vector<array<int, 3>> clean;
for (auto &x : e[i]) {
while (!clean.empty() && clean.back()[1] >= x[1]) {
clean.pop_back();
}
clean.pb(x);
}
e[i] = clean;
if (e[i].empty()) {
continue;
}
re[i + 1] = e[i];
for (auto &x : re[i + 1]) {
swap(x[0], x[1]);
x[0] = -x[0];
x[1] = -x[1];
}
sort(all(re[i + 1]));
}
vector<vector<pii>> binup(LOG_N, vector<pii>(ind)), rbinup(LOG_N, vector<pii>(ind));
for (int i = 0; i < ind; ++i) {
if (indexes[i][0] == n - 2) {
binup[0][i] = mp(i, 0);
} else {
auto it = lower_bound(all(e[indexes[i][0] + 1]), array<int, 3>{indexes[i][2], 0ll, 0ll});
int delta = 0;
if (it == e[indexes[i][0] + 1].end()) {
it = e[indexes[i][0] + 1].begin();
delta = t;
}
binup[0][i] = mp((*it)[2], delta);
}
if (indexes[i][0] == 0) {
rbinup[0][i] = mp(i, 0);
} else {
auto it = lower_bound(all(re[indexes[i][0]]), array<int, 3>{-indexes[i][1], (int)-1e9, (int)-1e9});
int delta = 0;
if (it == re[indexes[i][0]].end()) {
it = re[indexes[i][0]].begin();
delta = t;
}
rbinup[0][i] = mp((*it)[2], delta);
}
}
for (int l = 1; l < LOG_N; ++l) {
for (int i = 0; i < ind; ++i) {
binup[l][i] = mp(binup[l - 1][binup[l - 1][i].f].f, binup[l - 1][binup[l - 1][i].f].s + binup[l - 1][i].s);
rbinup[l][i] = mp(rbinup[l - 1][rbinup[l - 1][i].f].f, rbinup[l - 1][rbinup[l - 1][i].f].s + rbinup[l - 1][i].s);
}
}
map<pii, int> ans;
int q;
cin >> q;
while (q--) {
int a, b;
cin >> a >> b;
--a; --b;
if (ans.count(mp(a, b)) == 0) {
int answer = 1e18;
int len = b - a - 1;
if (e[a].size() < re[b].size()) {
for (auto &x : e[a]) {
int v = x[2];
int now = 0;
for (int l = 0; l < LOG_N; ++l) {
if (len&(1<<l)) {
now += binup[l][v].s;
v = binup[l][v].f;
}
}
answer = min(answer, now + indexes[v][2] - x[0]);
}
} else {
for (auto &x : re[b]) {
int v = x[2];
int now = 0;
for (int l = 0; l < LOG_N; ++l) {
if (len&(1<<l)) {
now += rbinup[l][v].s;
v = rbinup[l][v].f;
}
}
// cout << now << ' ' << indexes[v][1] << ' ' << x[1] << endl;
answer = min(answer, now - indexes[v][1] - x[0]);
}
}
ans[mp(a, b)] = answer;
}
cout << ans[mp(a, b)] << endl;
}
}
signed main() {
#ifdef LOCAL
freopen("in.txt", "r", stdin);
freopen("out.txt", "w", stdout);
#else
ios::sync_with_stdio(false);
cin.tie(0);
#endif
int t = 1;
// cin >> t;
while (t--) solve();
}
