#include <bits/stdc++.h>
#define pll pair<long long, long long>
using namespace std;
struct thing
{
long long nxt, day;
};
thing jump[100005][20], p;
long long l[100005], r[100005], id[100005], mn[100005];
pll a[100005];
bool sortt(long long x, long long y) {return a[x]<a[y];}
bool sorttt(long long x, long long y) {return a[x].second<a[y].second;}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
long long n, T, q, i, j, k=1, h;
cin >> n >> T;
for (i=1; i<n; i++)
{
cin >> j;
l[i]=r[i-1]+1; r[i]=l[i]+j-1; h=T-1;
while (j--)
{
cin >> a[k].first >> a[k].second;
if (a[k].second<h) {mn[i]=k; h=a[k].second;};
id[k]=k; k++;
};
};
for (i=n-1; i>=1; i--)
{
if (i<n-1) {sort(id+l[i+1], id+r[i+1]+1, sortt);}
else {continue;};
sort(id+l[i], id+r[i]+1, sorttt);
k=r[i+1]; p={mn[i+1], 1LL};
for (j=r[i]; j>=l[i]; j--)
{
while (k>=l[i+1] && a[id[k]].first>=a[id[j]].second)
{
if (p.day==1) {p={id[k], 0LL};}
else if (a[id[k]].second<a[p.nxt].second) {p={id[k], p.day};};
k--;
};
jump[id[j]][0]=p;
for (h=1; i+(1LL<<h)<n; h++)
{
jump[id[j]][h]={jump[jump[id[j]][h-1].nxt][h-1].nxt, jump[id[j]][h-1].day+jump[jump[id[j]][h-1].nxt][h-1].day};
};
};
};
cin >> q;
while (q--)
{
cin >> i >> j;
long long ans=T*n;
k=j-i-1;
for (long long x=l[i]; x<=r[i]; x++)
{
thing xx={x, 0LL};
for (h=0; (1LL<<h)<=k; h++)
{
if (k&(1LL<<h)) {xx={jump[xx.nxt][h].nxt, xx.day+jump[xx.nxt][h].day};};
};
ans=min(ans, a[xx.nxt].second-a[x].first+T*xx.day);
};
cout << ans << "\n";
};
}
