#include <bits/stdc++.h>
using namespace std;
#define int long long
int32_t main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int n,d;
cin >> n >> d;
vector<int> arr(n+1);
for(int i=1;i<=n;i++)cin>>arr[i];
vector<int> curr(n+1);
vector<int> actreq(n+1);
vector<int> req(n+1);
vector<int> preq(n+1);
int offset = 0;
for(int i=1;i<=n;i++){
curr[i] = curr[i-1]+((d+(arr[i]%d)-(curr[i-1]%d))%d);
req[i] = actreq[i] = (arr[i]-curr[i])/d;
offset = min(offset,actreq[i]);
}
offset = -offset;
for(int i=1;i<=n;i++)req[i]+=offset;
for(int i=1;i<=n;i++)preq[i]=req[i]+preq[i-1];
vector<vector<int>> lift(n+1,vector<int>(19));
vector<vector<int>> liftsum(n+1,vector<int>(19));
{
stack<pair<int,int>> s;
s.emplace(0,0);
for(int i=1;i<=n;i++){
while(s.top().first>req[i])s.pop();
lift[i][0] = s.top().second;
liftsum[i][0] = req[i]*(i-s.top().second);
s.emplace(req[i],i);
}
for(int bit=1;bit<=18;bit++){
for(int i=1;i<=n;i++){
lift[i][bit] = lift[lift[i][bit-1]][bit-1];
liftsum[i][bit] = liftsum[lift[i][bit-1]][bit-1]+liftsum[i][bit-1];
}
}
}
int q;
cin >> q;
for(int i=1;i<=q;i++){
int l,r;cin>>l>>r;
int ans = preq[r]-preq[l-1];
for(int bit=18;bit>=0;bit--){
if(lift[r][bit]>=l){
ans-=liftsum[r][bit];
r = lift[r][bit];
}
}
ans-=req[r]*(r-l+1);
if(actreq[r]+curr[l]/d>=0)cout<<ans<<'\n';
else cout << "-1\n";
}
}
