/**
* author: tourist
* created: 29.04.2025 17:36:20
**/
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "algo/debug.h"
#else
#define debug(...) 42
#endif
struct Segment {
int l, r;
Segment(int _l, int _r) : l(_l), r(_r) {}
};
class segtree {
public:
vector<__int128> sums, add;
int n;
segtree(int _n) : n(_n) {
sums.resize(4 * n);
add.resize(4 * n);
}
void modify(int l, int r, __int128 x, int ll, int rr, int v) {
if (ll >= r || l >= rr) {
return;
}
if (ll >= l && rr <= r) {
add[v] += x;
sums[v] += ((__int128) (rr - ll)) * x;
return;
}
int m = (ll + rr) >> 1;
modify(l, r, x, ll, m, 2 * v + 1);
modify(l, r, x, m, rr, 2 * v + 2);
sums[v] = sums[2 * v + 1] + sums[2 * v + 2];
}
void modify(int l, int r, int x) {
modify(l, r, x, 0, n, 0);
}
__int128 get(int l, int r, int ll, int rr, int v) {
if (ll >= l && rr <= r) {
return sums[v];
}
if (ll >= r || l >= rr) {
return 0;
}
int m = (ll + rr) >> 1;
add[2 * v + 1] += add[v];
add[2 * v + 2] += add[v];
sums[2 * v + 1] += ((__int128) (m - ll)) * add[v];
sums[2 * v + 2] += ((__int128) (rr - m)) * add[v];
add[v] = 0;
return get(l, r, ll, m, 2 * v + 1) + get(l, r, m, rr, 2 * v + 2);
}
__int128 get(int l, int r) {
return get(l, r, 0, n, 0);
}
};
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n;
cin >> n;
long long d;
cin >> d;
vector<long long> a(n + 1);
for (int i = 1; i <= n; i++) {
cin >> a[i];
}
vector<vector<pair<int, int>>> at(n + 1);
int q;
cin >> q;
for (int qq = 0; qq < q; qq++) {
int l, r;
cin >> l >> r;
at[r].emplace_back(l, qq);
}
vector<long long> ans(q);
vector<Segment> st;
st.push_back(Segment(0, 0));
segtree seg(n + 1);
for (int i = 1; i <= n; i++) {
st.push_back(Segment(i, i));
while (st.size() >= 2) {
Segment top = st.back(), sec = st[st.size() - 2];
__int128 sf = a[top.l] - (d * seg.get(top.l, top.l + 1)), fs = a[sec.r] - (d * seg.get(sec.r, sec.r + 1));
if (sf >= fs) {
break;
} else {
__int128 more = (fs - sf + d - 1) / d;
seg.modify(sec.l, sec.r + 1, more);
st.pop_back();
st.pop_back();
st.push_back(Segment(sec.l, top.r));
}
}
for (auto [l, id] : at[i]) {
ans[id] = seg.get(l, i + 1);
if (a[l] < (__int128) d * (__int128) seg.get(l, l + 1)) {
ans[id] = -1;
}
}
}
for (int i = 0; i < q; i++) {
cout << ans[i] << '\n';
}
return 0;
}
