//ahussssssssssss
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define bit(x,y) ((x >> y) & 1LL)
const ll N = 3e5 + 5;
const ll mod = 1e9 + 7;
const ll inf = LLONG_MAX/4;
struct segtree
{
ll n;
ll b[N * 4],sz[N * 4],lz[N * 4];
void build(ll n)
{
this->n = n;
build(0,1,n);
}
void build(ll x, ll l, ll r)
{
if(l == r)
{
b[x] = lz[x] = 0;
sz[x] = 1;
}else
{
ll mid = (l + r) / 2;
build(x * 2 + 1,l,mid);
build(x * 2 + 2,mid + 1,r);
sz[x] = sz[x * 2 + 1] + sz[x * 2 + 2];
}
}
void udt(ll l, ll r, ll add)
{
udt(0,1,n,l,r,add);
}
void push(ll x)
{
ll x1 = x * 2 + 1;
ll x2 = x1 + 1;
b[x1] += lz[x] * sz[x1];
b[x2] += lz[x] * sz[x2];
lz[x1] += lz[x];
lz[x2] += lz[x];
lz[x] = 0;
}
void udt(ll x, ll l, ll r, ll s, ll e, ll add)
{
if(e < l || r < s) return;
if(s <= l && r <= e)
{
b[x] += sz[x] * add;
lz[x] += add;
return;
}
push(x);
ll mid = (l + r) / 2;
udt(x * 2 + 1,l,mid,s,e,add);
udt(x * 2 + 2,mid + 1,r,s,e,add);
b[x] = b[x * 2 + 1] + b[x * 2 + 2];
}
ll get(ll x)
{
return get(x,x);
}
ll get(ll l, ll r)
{
return get(0,1,n,l,r);
}
ll get(ll x, ll l, ll r, ll s, ll e)
{
if(e < l || r < s) return 0;
if(s <= l && r <= e) return b[x];
push(x);
ll mid = (l + r) / 2;
return get(x * 2 + 1,l,mid,s,e) + get(x * 2 + 2,mid + 1,r,s,e);
}
};
segtree f;
ll a[N];
vector<pair<ll,ll>> qr[N];
ll ans[N];
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
ll n,d;
cin >> n >> d;
f.build(n);
ll i,j;
for(i = 1;i <= n;i++)
{
cin >> a[i];
}
ll q;
cin >> q;
for(i = 1;i <= q;i++)
{
ll l,r;
cin >> l >> r;
qr[r].push_back({l,i});
}
vector<pair<ll,ll>> sus;
for(i = 1;i <= n;i++)
{
ll hehe = i;
while(!sus.empty())
{
ll s = sus.back().first;
ll e = sus.back().second;
sus.pop_back();
ll t1 = a[e] - d * f.get(e);
ll t2 = a[e + 1] - d * f.get(e + 1);
if(t1 <= t2) break;
ll t = t1 - t2;
ll add = t / d;
if(t % d != 0) add++;
f.udt(s,e,add);
hehe = s;
}
sus.push_back({hehe,i});
for(auto tmp : qr[i])
{
if(d * f.get(tmp.first) > a[tmp.first]) ans[tmp.second] = -1;
else ans[tmp.second] = f.get(tmp.first,i);
}
}
for(i = 1;i <= q;i++) cout << ans[i] << "\n";
}
