#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define for1(i,j,k) for(int i=j;i<=k;i++)
#define for2(i,j,k) for(int i=j;i>=k;i--)
#define for3(i,j,k,l) for(int i=j;i<=k;i+=l)
#define all(x) x.begin(),x.end()
#define int long long
typedef long long ll;
typedef pair<int,int> pii;
typedef double db;
const ll maxn=(1<<18)+69;
const ll offset=2e5;
const ll inf=1e18;
const int base=350;
const ll mod=1e9+7;
int n,d;
int st[maxn*4],lazy[maxn*4];
vector<pii> qr[maxn];
int a[maxn],b[maxn],c[maxn],pre[maxn],x[maxn],ans[maxn];
void push_down(int id,int l,int r)
{
int mid=l+r>>1;
int& v=lazy[id];
st[id*2]+= v*(mid-l+1);
lazy[id*2]+=v;
st[id*2+1]+=v*(r-mid);
lazy[id*2+1]+=v;
v=0;
}
void Update(int u,int v,int val,int id=1,int l=1,int r=n)
{
if (u>r || v<l) return;
if (u<=l && r<=v)
{
st[id]+=val*(r-l+1);
lazy[id]+=val;
return;
}
int mid=l+r>>1;
if (lazy[id]!=0) push_down(id,l,r);
Update(u,v,val,id*2,l,mid);
Update(u,v,val,id*2+1,mid+1,r);
st[id]=st[id*2]+st[id*2+1];
}
int Get(int u,int v,int id=1,int l=1,int r=n)
{
if (u>r || v<l) return 0;
if (u<=l && r<=v) return st[id];
int mid=l+r>>1;
if (lazy[id]!=0) push_down(id,l,r);
return Get(u,v,id*2,l,mid)+ Get(u,v,id*2+1,mid+1,r);
}
void sol()
{
cin >> n>>d;
for1(i,1,n) cin >> a[i];
for1(i,1,n)
{
b[i]=a[i]%d;
c[i]=a[i]/d;
pre[i]=pre[i-1]+c[i];
x[i]=x[i-1]+(b[i]<b[i-1]);
}
int q; cin >>q;
for1(i,1,q)
{
int l,r; cin >> l>>r;
qr[r].pb({l,i});
}
vector<pii> L;
L.pb({-inf,0});
for1(i,1,n)
{
Update(i,i,c[i]);
// cerr<<"cccdc "<<i<<' '<<c[i]<<'\n';
while (!L.empty() && L.back().fi>=c[i]-x[i])
{
int j=L.back().se;
int cj=L.back().fi;
// cerr<< j<<'\n';
L.pop_back();
Update(L.back().fi+1,j,c[i]-x[i]-cj);
}
L.pb({c[i]-x[i],i});
for(auto [l,j]:qr[i])
{
if (Get(l,l)<0) {ans[j]=-1; continue;}
ans[j]=pre[i]-pre[l-1]-Get(l,i);
}
}
for1(i,1,q) cout << ans[i]<<'\n';
}
int32_t main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
// freopen("990G.inp","r",stdin);
// freopen("990G.out","w",stdout);
int t=1;//cin >> t;
for1(i,1,t) {
// cout << "Case #"<<i<<": ";
sol();
}
}
/*
4 12
1 2 3
1 3
2 3
2 1
1 2
1 2
1 4
1 1
1 1
2 4
2 3
1 1
3 4
*/
