// JOI 2024 (Fish 3)
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define fi first
#define se second
#define ins insert
#define eb emplace_back
void sol()
{
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), actreq(n+1), req(n+1), 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().fi>req[i])s.pop();
lift[i][0] = s.top().se;
liftsum[i][0] = req[i]*(i-s.top().se);
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";
}
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(nullptr);
sol();
return 0;
}
