#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ld long double
#define show(x,y) cout << y << " " << #x << endl;
#define show2(x,y,i,j) cout << y << " " << #x << " " << j << " " << #i << endl;
#define show3(x,y,i,j,p,q) cout << y << " " << #x << " " << j << " " << #i << " " << q << " " << #p << endl;
#define show4(x,y) for(auto it:y) cout << it << " "; cout << #x << endl;
typedef pair<int,int>pii;
typedef pair<int,pii>pi2;
mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());
int two[22][100005];
int dp[22][100005];
int offset[100005];
vector<pii>adj[100005];
const int blk=-1;
void solve(){
int n,k;
cin >> n >> k;
vector<pii>storage[n+5];
for(int x=1;x<n;x++){
int m;
cin >> m;
int temp,temp2;
for(int y=0;y<m;y++){
cin >> temp >> temp2;
storage[x].push_back({temp,temp2});
}
}
int q;
cin >> q;
int l,r;
for(int x=0;x<q;x++){
cin >> l >> r;
r--;
int dp[n+5][6];
memset(dp,63,sizeof(dp));
for(int i=0;i<(int)storage[l].size();i++){
dp[l][i]=storage[l][i].second-storage[l][i].first;
}
for(int y=l;y<r;y++){
for(int i=0;i<(int)storage[y].size();i++){
for(int j=0;j<(int)storage[y+1].size();j++){
if(storage[y][i].second<=storage[y+1][j].first){
dp[y+1][j]=min(dp[y+1][j],dp[y][i]+storage[y+1][j].second-storage[y][i].second);
}
else{
dp[y+1][j]=min(dp[y+1][j],dp[y][i]+storage[y+1][j].second-storage[y][i].second+k);
}
}
}
}
int best=1e18;
for(int i=0;i<6;i++) best=min(best,dp[r][i]);
cout << best << "\n";
}
}
int32_t main(){
ios::sync_with_stdio(0);
cin.tie(0);
//freopen("in.txt","r",stdin);
//freopen("out.txt","w",stdout);
int t=1;
//cin >> t;
while(t--){
solve();
}
}
