#include <bits/stdc++.h>
using namespace std;
#ifdef DEBUG
#include "/home/hp/contests/joi24scd4/debug.h"
#else
#define debug(...) void(37)
#endif
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
int N, T;
cin >> N >> T;
vector<vector<array<int, 2>>> g(N);
for (int i = 0; i < N - 1; ++i) {
int M;
cin >> M;
vector<int> A(M), B(M);
for (int j = 0; j < M; ++j) {
cin >> A[j] >> B[j];
}
vector<int> ord(M);
iota(ord.begin(), ord.end(), 0);
sort(ord.begin(), ord.end(), [&](int x, int y) {
return A[x] < A[y];
});
vector<int> st;
for (auto x: ord) {
while (!st.empty() && B[st.back()] >= B[x]) {
st.pop_back();
}
st.push_back(x);
}
for (auto x : st) {
g[i].push_back({A[x], B[x]});
}
}
vector<int> pref(N + 1);
vector<array<int, 2>> info;
for (int i = 0; i < N; ++i) {
pref[i + 1] = pref[i] + int(g[i].size());
for (auto x : g[i]) {
info.push_back(x);
}
}
debug(g, pref, info);
auto Id = [&](int i, int j) {
assert(j < int(g[i].size()));
return pref[i] + j;
};
auto Next = [&](int i, int t) -> array<int, 2> {
int ind = lower_bound(g[i].begin(), g[i].end(), array<int, 2>{t, -1}) - g[i].begin();
if (ind == int(g[i].size())) {
return {0, 1};
} else {
return {ind, 0};
}
};
int s = pref[N];
int LG = __lg(N) + 1;
vector<vector<int>> lift(LG, vector<int>(s, -1));
vector<vector<int>> cost(LG, vector<int>(s));
for (int i = 0; i < N - 2; ++i) {
for (int j = 0; j < int(g[i].size()); ++j) {
auto[to, _cost] = Next(i + 1, g[i][j][1]);
lift[0][Id(i, j)] = Id(i + 1, to);
cost[0][Id(i, j)] = _cost;
}
}
for (int l = 1; l < LG; ++l) {
for (int i = 0; i < s; ++i) {
int to = lift[l - 1][i];
if (to == -1) {
lift[l][i] = -1;
} else {
lift[l][i] = lift[l - 1][to];
cost[l][i] = cost[l - 1][i] + cost[l - 1][to];
}
}
}
auto Find_dist = [&](int v, int dist) -> int64_t {
int days = 0;
int start = info[v][0];
for (int i = 0; dist > 0; ++i, dist >>= 1) {
if (dist % 2) {
days += cost[i][v];
v = lift[i][v];
}
}
return 1LL * days * T + info[v][1] - start;
};
debug(lift, cost);
int Q;
cin >> Q;
while (Q--) {
int L, R;
cin >> L >> R;
--L, --R;
int64_t ans = int64_t(1e18);
for (int j = 0; j < int(g[L].size()); ++j) {
ans = min(ans, Find_dist(Id(L, j), R - L - 1));
}
cout << ans << '\n';
}
}
