#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 1e5 + 10;
const int L = 17;
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
int n;
ll t;
cin >> n >> t;
vector<vector<pair<int, int>>> a(n);
vector<vector<int>> xs(n);
for (int i = 0; i < n - 1; ++i) {
int m;
cin >> m;
a[i].resize(m);
for (auto & [x, y]: a[i]) {
cin >> x >> y;
}
sort(a[i].begin(), a[i].end());
vector<pair<int, int>> b;
for (auto [x, y]: a[i]) {
if (b.size() && b.back().first == x) continue;
while (b.size() && b.back().second >= y) b.pop_back();
b.emplace_back(x, y);
}
a[i] = b;
for (auto [x, y]: a[i]) {
xs[i].push_back(x);
xs[i + 1].push_back(y);
}
}
vector<map<int, int>> id(n);
map<int, pair<int, int>> to;
vector<int> day;
int ci = 0;
for (int i = 0; i < n; ++i) {
sort(xs[i].begin(), xs[i].end());
xs[i].erase(unique(xs[i].begin(), xs[i].end()), xs[i].end());
for (auto x: xs[i]) {
day.push_back(i);
id[i][x] = ci++;
to[ci - 1] = {i, x};
}
}
vector<set<int>> ex(n);
for (int i = 0; i < n - 1; ++i) {
for (auto [x, y]: a[i]) {
ex[i].insert(x);
}
}
day.push_back(n);
ci++;
to[ci - 1] = {n, -1};
vector<vector<pair<int, ll>>> g(ci);
for (int i = 0; i < n - 1; ++i) {
for (int j = 0; j < a[i].size(); ++j) {
int tx = a[i][j].first, ty = a[i][j].second;
int x = id[i][tx], y = id[i + 1][ty];
g[y].push_back({x, ty - tx});
if (i == n - 2) {
g[ci - 1].push_back({y, 0});
} else {
auto it = ex[i + 1].lower_bound(ty);
if (it == ex[i + 1].end()) {
int nt = *(ex[i + 1].begin());
int tt = nt + t - ty;
g[id[i + 1][nt]].push_back({y, tt});
} else if ((*it) != ty) {
g[id[i + 1][*it]].push_back({y, (*it) - ty});
}
}
}
}
const ll inf = 1e18;
vector<ll> dt(ci, inf); // distance to last node that is different
vector<int> par(ci, -1);
function<void(int)> dfs = [&] (int x) {
for (auto [y, w]: g[x]) {
assert(day[y] == day[x] || day[y] == day[x] - 1);
par[y] = x;
dfs(y);
if (day[y] != day[x]) {
if (w < dt[x]) {
dt[x] = w;
}
} else {
if (w + dt[y] < dt[x]) {
dt[x] = w + dt[y];
}
}
}
sort(g[x].begin(), g[x].end(), [&](const pair<int, ll> & y, const pair<int, ll> & z) {
ll vy = day[y.first] != day[x] ? y.second : y.second + dt[y.first];
ll vz = day[z.first] != day[x] ? z.second : z.second + dt[z.first];
return vy < vz;
});
};
dfs(ci - 1);
int q;
cin >> q;
vector<vector<pair<int, int>>> qu(n + 1);
map<pair<int, int>, int> has;
vector<ll> ans(q, inf);
for (int i = 0; i < q; ++i) {
int x, y;
cin >> x >> y;
x--; y--;
if (has.find({x, y}) != has.end()) {
ans[i] = -1 - has[{x, y}];
} else {
has[{x, y}] = i;
qu[x].push_back({y, i});
}
}
for (auto & v: qu) {
sort(v.begin(), v.end());
}
vector<int> vis(n + 1, 0);
vector<ll> path;
function<int(int, int, int)> dfs2 = [&] (int x, int top, int exc) {
assert(n - day[x] == path.size() - 1);
// cout << "!!! " << x << ' ' << day[x] << ' ' << top << ' ' << ' ' << exc << ' ' << path.back() << '\n';
if (x != ci - 1 && day[par[x]] != day[x]) {
for (auto [i, qi]: qu[day[x]]) {
// if (i > top && vis[day[x]]) break;
if (i > top && day[x] >= exc) break;
ll dist = path.back();
dist -= path[n - i];
// cout << n << ' ' << i << ' ' << path.size() << '\n';
ans[qi] = min(ans[qi], dist);
}
// not vis[x] -> dont go past top
// vis[day[x]]++;
}
int mx = day[x];
int cd = -1;
for (auto [y, w]: g[x]) {
if (day[y] == day[x]) path.back() += w;
else path.push_back(path.back() + w);
int dep = dfs2(y, y == g[x][0].first ? top : day[y], cd == -1 ? (1 << 25) : cd);
mx = min(mx, dep);
cd = (cd == -1 ? dep : min(cd, dep));
if (day[y] == day[x]) path.back() -= w;
else path.pop_back();
}
return mx;
};
path.push_back(0LL);
// path[0] = n
dfs2(ci - 1, n, (1 << 25));
for (auto & x: ans) {
if (x < 0) x = ans[-(x + 1)];
cout << x << "\n";
}
}
