#include <bits/stdc++.h>
#define ll long long
#define str string
#define ins insert
#define ld long double
#define pb push_back
#define pf push_front
#define pof pop_front()
#define pob pop_back()
#define lb lower_bound
#define ub upper_bound
#define endl "\n"
#define fr first
#define sc second
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define sz size()
#define vll vector<ll>
#define bc back()
#define arr array
#define pll vector<pair<ll,ll>>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ordered_set tree<ll, null_type,less_equal<ll>, rb_tree_tag,tree_order_statistics_node_update>
template<class S,class T>
bool chmin(S &a,const T &b) {
return a>b?(a=b)==b:false;
}
template<class S,class T>
bool chmax(S &a,const T &b) {
return a<b?(a=b)==b:false;
}
//void fre(string s){freopen((s+".in").c_str(),"r",stdin);freopen((s+".out").c_str(),"w",stdout);}
void start(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
}
const ll inf=1e18;
const ll mod=998244353;
const ll N=3e5+7;
const ll M=1e5+7;
const ld eps=1e-9;
ll d;
struct ST{
pll t;
vll add;
void init(){
t.assign(N*4,{0,0});
add.assign(N*4,0);
}
void push(ll v,ll tl,ll tr){
if(tl!=tr){
add[v*2]+=add[v];
add[v*2+1]+=add[v];
}
t[v].fr-=add[v]*d;
t[v].sc+=(tr-tl+1)*add[v];
add[v]=0;
}
void upd(ll id,ll l,ll r,ll val,ll v=1,ll tl=1,ll tr=N){
push(v,tl,tr);
if(tl>r || tr<l)return;
if(l<=tl && tr<=r){
if(id==0)t[v].fr=val;
else{
add[v]=val;
push(v,tl,tr);
}
return;
}ll tm=(tl+tr)/2;
upd(id,l,r,val,v*2,tl,tm);
upd(id,l,r,val,v*2+1,tm+1,tr);
t[v].sc=t[v*2].sc+t[v*2+1].sc;
}
ll get(ll id,ll l,ll r,ll v=1,ll tl=1,ll tr=N){
push(v,tl,tr);
if(tl>r || tr<l)return 0;
if(l<=tl && tr<=r) return (id==0 ? t[v].fr : t[v].sc);
ll tm=(tl+tr)/2;
return get(id,l,r,v*2,tl,tm)+get(id,l,r,v*2+1,tm+1,tr);
}
}t;
void solve(){
ll i,j;
ll n;
cin>>n>>d;
t.init();
for(i=1;i<=n;i++){
ll x;
cin>>x;
t.upd(0,i,i,x);
}
ll q;
cin>>q;
vector<pll> qq(n+5);
ll ans[q+5];
for(i=0;i<q;i++){
ll l,r;
cin>>l>>r;
qq[r].pb({l,i});
}
pll v;
v.pb({1,1});
for(auto i : qq[1]){
ans[i.sc]=0;
}
for(i=2;i<=n;i++){
ll l=i,r=i;
while(v.sz){
ll x=v.bc.fr,y=v.bc.sc;
ll k=t.get(0,y,y);
ll m=t.get(0,l,l);
if(k<m){
if(m-k>=d){v.pb({l,r});break;}
else l=x;
}else{
t.upd(1,x,y,(k-m+d-1)/d);
l=x;
}
v.pob;
}
v.pb({l,r});
for(auto j : qq[i]){
if(t.get(0,j.fr,j.fr)<0)ans[j.sc]=-1;
else ans[j.sc]=t.get(1,j.fr,i);
}
}
for(i=0;i<q;i++) cout<<ans[i]<<endl;
}
signed main(){
start();
ll t=1;
//cin>>t;
while(t--) solve();
return 0;
}
/*
7 10
1 2
1 3
4 2
100 1
100 2
100 3
300 2
*/
