#include<bits/stdc++.h>
#define int long long
using namespace std;
const int N = 300010;
const int inf = 1e18;
const int debug = 0;
int n, q, d;
vector <pair <int, int>> intervalos;
int h[N];
vector <pair <int, int>> queries;
map <pair <int, int>, int> res;
set <int> s[N];
struct Segtree{
int tree[4*N], lazy[4*N];
int join(int a, int b){
return min(a, b);
}
void unlazy(int node, int l, int r){
tree[node] += lazy[node];
if(l != r) {
lazy[2*node] += lazy[node];
lazy[2*node+1] += lazy[node];
}
lazy[node] = 0;
}
void build(int node, int l, int r){
if(l == r){
tree[node] = h[l];
lazy[node] = 0;
return;
}
int mid = (l+r)/2;
build(2*node, l, mid);
build(2*node+1, mid+1, r);
tree[node] = join(tree[2*node], tree[2*node+1]);
lazy[node] = 0;
return;
}
void update(int node, int l, int r, int tl, int tr, int val){
unlazy(node, tl, tr);
if(l > tr or tl > r) return;
if(l <= tl and tr <= r){
lazy[node] += val;
unlazy(node, tl, tr);
return;
}
int mid = (tl+tr)/2;
update(2*node, l, r, tl, mid, val);
update(2*node+1, l, r, mid+1, tr, val);
tree[node] = join(tree[2*node], tree[2*node+1]);
return;
}
int query(int node, int l, int r, int tl, int tr){
unlazy(node, tl, tr);
if(l > tr or tl > r) return inf;
if(l <= tl and tr <= r) return tree[node];
int mid = (tl+tr)/2;
return join(query(2*node, l, r, tl, mid), query(2*node+1, l, r, mid+1, tr));
}
} alturas;
struct Segtree2{
int tree[4*N], lazy[4*N];
int join(int a, int b){
return a+b;
}
void unlazy(int node, int l, int r){
tree[node] += lazy[node]*(r-l+1);
if(l != r){
lazy[2*node] += lazy[node];
lazy[2*node+1] += lazy[node];
}
lazy[node] = 0;
}
void build(int node, int l, int r){
if(l == r){
tree[node] = 0;
lazy[node] = 0;
return;
}
int mid = (l+r)/2;
build(2*node, l, mid);
build(2*node+1, mid+1, r);
tree[node] = join(tree[2*node], tree[2*node+1]);
lazy[node] = 0;
return;
}
void update(int node, int l, int r, int tl, int tr, int val){
unlazy(node, tl, tr);
if(l > tr or tl > r) return;
if(l <= tl and tr <= r){
lazy[node] += val;
unlazy(node, tl, tr);
return;
}
int mid = (tl+tr)/2;
update(2*node, l, r, tl, mid, val);
update(2*node+1, l, r, mid+1, tr, val);
tree[node] = join(tree[2*node], tree[2*node+1]);
return;
}
int query(int node, int l, int r, int tl, int tr){
unlazy(node, tl, tr);
if(l > tr or tl > r) return 0;
if(l <= tl and tr <= r) return tree[node];
int mid = (tl+tr)/2;
return join(query(2*node, l, r, tl, mid), query(2*node+1, l, r, mid+1, tr));
}
} resposta;
int32_t main(){
cin >> n >> d;
for(int i = 1;i <= n;i++)
cin >> h[i];
alturas.build(1, 1, n);
cin >> q;
for(int i = 0;i < q;i++){
int a, b;
cin >> a >> b;
queries.push_back({a, b});
s[b].insert(a);
}
res[{1, 1}] = 0;
intervalos.push_back({1, 1});
for(int r = 2;r <= n;r++){
if(h[r] >= h[r-1]){
if(h[r]-d < h[r-1]){
auto [p, _] = intervalos.back();
intervalos.pop_back();
intervalos.push_back({p, r});
}
else intervalos.push_back({r, r});
}
else{
auto [p, q] = intervalos.back();
int res;
int alt = h[r];
if(debug and r == 3){
cout << '(' << q << ' ' << alturas.query(1, q, q, 1, n) << ' ';
cout << alt << ' ' << (alturas.query(1,q, q, 1, n) > alt) << ')';
}
while(alturas.query(1, q, q, 1, n) > alt){
int t = (-(alt - alturas.query(1, q, q, 1, n))+d-1)/d;
//cout << t << 'a';
alturas.update(1, p, q, 1, n, -t*d);
resposta.update(1, p, q, 1, n, t);
alt = alturas.query(1, p, p, 1, n);
intervalos.pop_back();
res = p;
if(intervalos.empty()) break;
p = intervalos.back().first;
q = intervalos.back().second;
}
intervalos.push_back({res, r});
}
if(debug){
for(int i = 1;i <= r;i++)
cout << resposta.query(1, i, r, 1, n) << ' ';
cout << '\n';
}
for(auto l : s[r]){
res[{l,r}] = (alturas.query(1, l, r, 1, n) < 0 ? -1 : resposta.query(1, l, r, 1, n));
}
}
if(debug) cout << '\n' << '\n';
for(auto x : queries){
cout << res[x] << '\n';
}
return 0;
}
