#include <bits/stdc++.h>
using i64 = long long;
#ifdef DEBUG
#include "/home/ahmetalp/Desktop/Workplace/debug.h"
#else
#define debug(...) void(23)
#endif
template<typename T>
bool chmin(T& a, T b) {
if (a > b) {
a = b;
return true;
}
return false;
}
constexpr i64 inf = i64(1E18);
constexpr int max_N = int(1E5) + 5;
constexpr int max_Q = int(3E5) + 5;
constexpr int LG = std::__lg(max_N) + 1;
constexpr int B = int(std::sqrt(max_N / LG));
int N;
int T;
int M[max_N];
std::vector<std::array<int, 2>> all;
std::vector<std::array<int, 2>> to[max_N];
std::vector<std::array<int, 2>> lift[LG];
int imp[max_N];
std::vector<i64> anses[(max_N + B - 1) / B];
int main() {
std::ios::sync_with_stdio(false);
std::cin.tie(nullptr);
std::cin >> N >> T;
for (int i = 1; i < N; ++i) {
std::cin >> M[i];
to[i].resize(M[i]);
for (int j = 0; j < M[i]; ++j) {
std::cin >> to[i][j][0] >> to[i][j][1];
}
std::sort(to[i].begin(), to[i].end());
std::vector<std::array<int, 2>> stk;
for (int j = 0; j < M[i]; ++j) {
while (!stk.empty() && stk.back()[1] >= to[i][j][1]) {
stk.pop_back();
}
stk.emplace_back(to[i][j]);
}
to[i] = std::move(stk);
M[i] = int(to[i].size());
all.insert(all.end(), to[i].begin(), to[i].end());
}
std::vector<int> ps(N + 1);
for (int i = 1; i < N; ++i) {
ps[i + 1] = ps[i] + int(to[i].size());
}
lift[0].resize(ps[N]);
for (int i = 1; i < N - 1; ++i) {
for (int j = 0; j < M[i]; ++j) {
int p = int(std::lower_bound(to[i + 1].begin(), to[i + 1].end(), std::array<int, 2>{to[i][j][1], -1}) - to[i + 1].begin());
if (p == M[i + 1]) {
lift[0][ps[i] + j] = {ps[i + 1] + 0, 1};
} else {
lift[0][ps[i] + j] = {ps[i + 1] + p, 0};
}
}
}
for (int j = 0; j < M[N - 1]; ++j) {
lift[0][ps[N - 1] + j] = {-1, -1};
}
for (int i = 1; i < LG; ++i) {
lift[i].resize(ps[N]);
for (int j = 0; j < ps[N]; ++j) {
auto[x, y] = lift[i - 1][j];
if (x == -1) {
lift[i][j] = {-1, -1};
} else {
auto[x1, y1] = lift[i - 1][x];
lift[i][j] = {x1, y + y1};
}
}
}
auto answer = [&](int v, int dt) -> i64 {
int d = 0;
int st = all[v][0];
for (int i = LG - 1; i >= 0; --i) {
if (dt >> i & 1) {
d += lift[i][v][1];
v = lift[i][v][0];
}
}
int en = all[v][1];
debug(en, st, d);
return en - st + 1LL * d * T;
};
for (int i = 1; i < N; ++i) {
if (M[i] > B) {
imp[i] = ++imp[0];
anses[imp[i]].resize(N + 1, inf);
std::vector<i64> dis(ps[N], inf);
for (int j = 0; j < M[i]; ++j) {
dis[ps[i] + j] = 0;
}
for (int j = i; j < N; ++j) {
for (int k = 0; k < M[j]; ++k) {
debug(ps[j] + k, dis[ps[j] + k], to[j][k]);
chmin(anses[imp[i]][j + 1], dis[ps[j] + k] + to[j][k][1] - to[j][k][0]);
if (j != N - 1) {
chmin(dis[lift[0][ps[j] + k][0]], dis[ps[j] + k] + all[lift[0][ps[j] + k][0]][0] - to[j][k][0] + lift[0][ps[j] + k][1] * T);
}
}
}
debug(dis);
debug(anses[imp[i]]);
}
}
int Q;
std::cin >> Q;
while (Q--) {
int L, R;
std::cin >> L >> R;
if (imp[L]) {
i64 res = anses[imp[L]][R];
std::cout << res << '\n';
} else {
i64 mn = inf;
for (int j = 0; j < M[L]; ++j) {
chmin(mn, answer(ps[L] + j, R - L - 1));
}
std::cout << mn << '\n';
}
}
return 0;
}
