#include <bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
#define all(v) v.begin(), v.end()
const int M = 3e5 + 1;
int seg[M*2], lz[M*2];
void push(int v,int s,int e)
{
int mid=(s+e)/2, lc=v+1, rc=v+(mid-s)*2;
seg[lc]=lz[v]*(mid-s), seg[rc]=lz[v]*(e-mid);
lz[lc]=lz[rc]=lz[v];
lz[v]=-1;
}
void modify(int l,int r,int x,int v=0,int s=0,int e=M)
{
if (l>=e or r<=s) return;
if (l<=s && e<=r)
{
seg[v]=x*(e-s), lz[v]=x;
return;
}
int mid=(s+e)/2, lc=v+1, rc=v+(mid-s)*2;
if (~lz[v]) push(v,s,e);
modify(l,r,x,lc,s,mid);
modify(l,r,x,rc,mid,e);
seg[v]=seg[lc]+seg[rc];
}
int get(int l,int r,int v=0,int s=0,int e=M)
{
if (l>=e or r<=s) return 0;
if (l<=s && e<=r) return seg[v];
int mid=(s+e)/2, lc=v+1, rc=v+(mid-s)*2;
if (~lz[v]) push(v,s,e);
return get(l,r,lc,s,mid)+get(l,r,rc,mid,e);
}
signed main()
{
ios::sync_with_stdio(0);
cin.tie(NULL), cout.tie(NULL);
for (int i=0;i<M*2;i++) lz[i]=-1;
int n,d;
cin>>n>>d;
int a[n];
for (int i=0;i<n;i++)
cin>>a[i];
if (n<=3000)
{
int q;
cin>>q;
int val[n];
while (q--)
{
int l,r;
cin>>l>>r;l--;
bool pos=1;
int cnt=0;
for (int i=l;i+1<r && pos;i++)
{
val[i]=a[i]/d-cnt;
if (a[i+1]%d<a[i]%d) cnt++;
}
val[r-1]=a[r-1]/d-cnt;
for (int i=l;i<r;i++)
if (val[i]<0) pos=0;
if (!pos)
{
cout<<-1<<endl;
continue;
}
int ans=0,mn=val[r-1];
for (int i=r-1;i>=l;i--)
mn=min(mn,val[i]), ans+=val[i]-mn;
cout<<ans<<endl;
}
}
else if(d==1)
{
int q;
cin>>q;
int ans[q], pre[n+1]={};
vector<pair<int,int>> v[n];
for (int i=0;i<q;i++)
{
int l,r;
cin>>l>>r;l--,r--;
v[r].push_back({l,i});
}
stack<pair<int,int>> st;
st.push({-1,-1});
for (int i=0;i<n;i++)
{
pre[i+1]=pre[i]+a[i];
while (!st.empty() && st.top().first>=a[i])
st.pop();
modify(st.top().second+1, i+1, a[i]);
for (auto [l,id]:v[i])
ans[id]=pre[i+1]-pre[l]-get(l,i+1);
st.push({a[i],i});
}
for (int i=0;i<q;i++)
cout<<ans[i]<<endl;
}
else
{
int pre[n+1]={};
vector<int> v;
for (int i=0;i<n;i++)
{
pre[i+1]=pre[i]+a[i];
if (!a[i]) v.push_back(i);
}
int q;
cin>>q;
while (q--)
{
int l,r;
cin>>l>>r;l--;
int x=lower_bound(all(v),r)-begin(v),ans=0;
if (x && pre[v[x-1]]>pre[l])
ans=(d>1?-1:pre[v[x-1]]-pre[l]);
cout<<ans<<endl;
}
}
return 0;
}
