#include <bits/stdc++.h>
using namespace std;
#define FOR(i, l, r) for(int i = (l); i < (r); ++i)
#define ROF(i, l, r) for(int i = (l) - 1; i >= (r); --i)
#define mp make_pair
#define mt make_tuple
#define ff first
#define ss second
#define all(v) begin(v), end(v)
#define rall(v) rbegin(v), rend(v)
#define sz(v) (int)v.size()
#define sum_of(v) accumulate(all(v), 0ll)
#define pb push_back
#define eb emplace_back
#define compact(v) v.erase(unique(all(v)), end(v))
#define dbg(x) "[" #x " = " << (x) << "]"
#define file(task) if(fopen(task".inp", "r")){ \
freopen(task".inp", "r", stdin); \
freopen(task".ans", "w", stdout); }
template<typename T>
bool minimize(T& a, const T& b){
if(a > b) return a = b, true;
return false;
}
template<typename T>
bool maximize(T& a, const T& b){
if(a < b) return a = b, true;
return false;
}
using ll = long long;
using db = double;
using ld = long double;
using ull = unsigned long long;
using pi = pair<int, int>;
using pl = pair<ll, ll>;
using pd = pair<db, db>;
using vi = vector<int>;
using vl = vector<ll>;
using vb = vector<bool>;
using vd = vector<db>;
using vpi = vector<pi>;
using vpl = vector<pl>;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
const int MAX = 2e3 + 5;
const ll inf = (ll)1e18;
int N, T;
vpi flights[MAX];
vl dp[MAX];
ll solve(int l, int r){
FOR(i, l, r){
if(i == l) fill(all(dp[i]), 0);
else fill(all(dp[i]), inf);
}
FOR(i, l, r){
if(i == r-1){
ll result = inf;
FOR(j, 0, sz(flights[i])){
minimize(result, dp[i][j] + flights[i][j].ss - flights[i][j].ff);
}
return result;
}
FOR(j, 0, sz(flights[i])){
int ai, bi; tie(ai, bi) = flights[i][j];
FOR(k, 0, sz(flights[i+1])){
int aj, bj; tie(aj, bj) = flights[i+1][k];
if(bi <= aj) minimize(dp[i+1][k], dp[i][j] + aj - ai);
else minimize(dp[i+1][k], dp[i][j] + T - ai + aj);
}
}
}
assert(0);
}
void testcase(int num_testcase){
cin >> N >> T;
FOR(i, 0, N-1){
int M;
cin >> M;
flights[i].resize(M);
dp[i].resize(M);
FOR(j, 0, M) cin >> flights[i][j].ff >> flights[i][j].ss;
}
int Q; cin >> Q;
while(Q--){
int l, r;
cin >> l >> r;
--l, --r;
cout << solve(l, r) << '\n';
}
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0);
// freopen("task.inp", "r", stdin);
file("task");
int T = 1;
// cin >> T;
FOR(i, 0, T) testcase(i);
return 0;
}
