#include <bits/stdc++.h>
#define all(x) x.begin(), x.end()
#define ar array
using namespace std;
typedef long long ll;
const int N = 1e5 + 5, K = 300;
ar <ll, 2> g[N], st[17][N];
ll prec[N / K + 3][N], prans[N / K + 3][N];
int id[N];
int main() {
ios::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
int n, t, f = 1;
cin >> n >> t;
vector <vector <ar <int, 3>>> a(n + 1), b(n + 1);
for (int i = 1; i < n; i++) {
int m;
cin >> m;
a[i].resize(m);
b[i].resize(m);
int mb = t, wh = -1;
for (int j = 0; j < m; j++) {
cin >> a[i][j][0] >> a[i][j][1];
a[i][j][2] = b[i][j][2] = f++;
if (mb > a[i][j][1]) {
mb = a[i][j][1];
wh = a[i][j][2];
}
b[i][j][0] = a[i][j][1];
b[i][j][1] = a[i][j][0];
}
sort(all(a[i]));
vector <ar <int, 2>> sf(m);
int mn = t, wmn = -1;
for (int j = m - 1; j >= 0; j--) {
if (mn > a[i][j][1]) {
mn = a[i][j][1];
wmn = a[i][j][2];
}
sf[j] = {mn, wmn};
}
if (i > 1) {
int j = i - 1;
for (auto now : a[j]) {
int k = lower_bound(all(a[i]), ar <int, 3>({now[1], -1, -1})) - a[i].begin();
if (k < m) {
g[now[2]] = {sf[k][1], sf[k][0] - now[1]};
} else {
g[now[2]] = {wh, mb + t - now[1]};
}
}
}
}
for (int i = 1; i < f; i++)
st[0][i] = g[i];
for (int i = 1; i < 17; i++) {
for (int j = 1; j < f; j++) {
st[i][j] = st[i - 1][st[i - 1][j][0]];
st[i][j][1] += st[i - 1][j][1];
}
}
int tmpp = 1;
for (int i = 1; i < n; i++) {
if (a[i].size() >= K) {
id[i] = tmpp++;
int ed = id[i];
for (int j = 1; j < f; j++)
prec[ed][j] = 1e18;
for (auto now : a[i])
prec[ed][now[2]] = now[1] - now[0];
for (int j = i; j < n; j++) {
ll mn = 1e18;
for (auto now : a[j]) {
mn = min(mn, prec[ed][now[2]]);
int nxt = g[now[2]][0];
prec[ed][nxt] = min(prec[ed][nxt], prec[ed][now[2]] + g[now[2]][1]);
}
prans[ed][j + 1] = mn;
}
}
}
int q;
cin >> q;
while (q--) {
int l, r;
cin >> l >> r;
if (a[l].size() >= K) {
cout << prans[id[l]][r] << '\n';
} else {
ll ans = 1e18;
for (auto now : a[l]) {
ll res = now[1] - now[0];
int dis = r - l - 1, b = 0, x = now[2];
while (dis) {
if (dis & 1) {
res += st[b][x][1];
x = st[b][x][0];
}
b++, dis >>= 1;
}
ans = min(ans, res);
}
cout << ans << '\n';
}
}
}
/*
4 10000
3
400 500
500 501
100 300
3
100 800
200 400
300 600
1
500 600
3
1 3
2 4
1 4
*/
