#include <bits/stdc++.h>
using namespace std;
#define int long long
const int INF = 1e18;
int n,d;
int c[300005];
int prefr[300005];
int rez[300005], qle[300005], qri[300005];
vector<int> qrys_ofri[300005];
int val[300005], pref_val[300005];
struct node
{
int minv = INF, sum = 0;
};
node combine(node x, node y)
{
node aux;
aux.minv = min(x.minv, y.minv);
aux.sum = x.sum + y.sum;
return aux;
}
node aint[1100000];
int lazy[1100000];
void build(int nod, int st, int dr)
{
lazy[nod] = INF;
aint[nod] = {};
if(st == dr)
return;
int mij = (st + dr) / 2;
build(nod*2,st,mij);
build(nod*2+1,mij+1,dr);
}
void handle(int nod, int newv, int st, int dr)
{
aint[nod].minv = newv;
aint[nod].sum = newv * (dr - st + 1);
lazy[nod] = newv;
}
void propagate(int nod, int st, int dr)
{
if(lazy[nod] == INF)
return;
int mij = (st + dr) / 2;
handle(nod*2, lazy[nod], st, mij);
handle(nod*2+1, lazy[nod], mij+1, dr);
lazy[nod] = INF;
}
void upd(int nod, int st, int dr, int le, int ri, int newv)
{
if(le > ri)
return;
if(le == st && dr == ri)
{
handle(nod, newv, st, dr);
return;
}
propagate(nod, st, dr);
int mij = (st + dr) / 2;
upd(nod*2,st,mij,le,min(mij,ri),newv);
upd(nod*2+1,mij+1,dr,max(mij+1,le),ri,newv);
aint[nod] = combine(aint[nod*2], aint[nod*2+1]);
}
node qry(int nod, int st, int dr, int le, int ri)
{
if(le > ri)
return {};
if(le == st && dr == ri)
return aint[nod];
propagate(nod,st,dr);
int mij = (st + dr) / 2;
return combine(qry(nod*2,st,mij,le,min(mij,ri)), qry(nod*2+1,mij+1,dr,max(mij+1,le),ri));
}
signed main()
{
ios_base::sync_with_stdio(0);cin.tie(0);
cin>>n>>d;
for(int i=1;i<=n;i++)
{
cin>>c[i];
prefr[i] = prefr[i-1] + ((c[i] - c[i-1]) % d + d) % d;
val[i] = c[i] - prefr[i];
pref_val[i] = pref_val[i-1] + val[i];
}
int q;
cin>>q;
for(int i=1;i<=q;i++)
{
cin>>qle[i]>>qri[i];
qrys_ofri[qri[i]].push_back(i);
}
vector<int> st;
val[0] = -INF;
st.push_back(0);
build(1,1,n);
for(int ri=1;ri<=n;ri++)
{
while(val[ri] < val[st.back()])
st.pop_back();
upd(1,1,n, st.back() + 1, ri, val[ri]);
st.push_back(ri);
for(int qid:qrys_ofri[ri])
{
int le = qle[qid];
int dif = prefr[le] - c[le] % d;
node aux = qry(1,1,n,le,ri);
int mnm = aux.minv, sum = aux.sum;
if(mnm + dif < 0)
{
rez[qid] = -1;
continue;
}
int tot = pref_val[ri] - pref_val[le-1];
assert((tot - sum) % d == 0);
rez[qid] = (tot - sum) / d;
}
}
for(int i=1;i<=q;i++)
cout<<rez[i]<<"\n";
return 0;
}
