#include <bits/stdc++.h>
using namespace std;
using ll = long long;
ll d;
const ll inf = 1e13;
const int N = 300005;
struct node {
ll sum, len, mn, lazy;
};
node operator + (node a, node b) {
return {a.sum + b.sum, a.len + b.len, min(a.mn, b.mn), inf};
}
node aint[4 * N];
void propag(int nod) {
if (aint[nod].lazy == inf)
return;
aint[nod].sum = aint[nod].len * aint[nod].lazy;
aint[nod].mn = aint[nod].lazy;
if (aint[nod].len > 1)
aint[2 * nod].lazy = aint[2 * nod + 1].lazy = aint[nod].lazy;
aint[nod].lazy = inf;
}
void build (int pos, int st, int dr) {
aint[pos] = {0, dr - st + 1, 0, inf};
if (st == dr)
return;
int mid = (st + dr) / 2;
build (2 * pos, st, mid);
build (2 * pos + 1, mid + 1, dr);
}
void update(int pos, int st, int dr, int l, int r, ll eq) {
propag(pos);
if (l <= st && dr <= r) {
aint[pos].lazy = eq;
propag(pos);
return;
}
int mid = (st + dr) / 2;
if (l <= mid)
update(2 * pos, st, mid, l, r, eq);
else
propag(2 * pos);
if (mid < r)
update(2 * pos + 1, mid + 1, dr, l, r, eq);
else
propag(2 * pos + 1);
aint[pos] = aint[2 * pos] + aint[2 * pos + 1];
}
node query(int pos, int st, int dr, int l, int r) {
propag(pos);
if (l <= st && dr <= r)
return aint[pos];
int mid = (st + dr) / 2;
if (r <= mid)
return query(2 * pos, st, mid, l, r);
else if (mid < l)
return query(2 * pos + 1, mid + 1, dr, l, r);
return query(2 * pos, st, mid, l, r) + query(2 * pos + 1, mid + 1, dr, l, r);
}
struct QRY {
int l, r, pos;
};
signed main() {
int n;
cin >> n >> d;
vector<ll> v(n);
for (int i = 0; i < n; i ++) {
ll c;
cin >> c;
v[i] = c;
}
auto nv = v;
ll scazi = 0;
for (int i = 0; i < n; i ++) {
nv[i] -= scazi;
scazi += (nv[i] % d + d) % d;
nv[i] -= (nv[i] % d + d) % d;
nv[i] /= d;
v[i] /= d;
}
build(1, 0, n - 1);
vector<ll> sp(n);
sp[0] = nv[0];
for (int i = 1; i < n; i ++)
sp[i] = sp[i - 1] + nv[i];
int q;
cin >> q;
vector<QRY> vq;
for (int i = 0; i < q; i ++) {
int l, r;
cin >> l >> r;
vq.push_back({l - 1, r - 1, i});
}
sort(vq.begin(), vq.end(), [&](QRY a, QRY b) {return a.r < b.r;});
vector<ll> ans(q);
stack<int> skyline;
vector<int> prev(n);
for (int i = n - 1; i >= 0; i --) {
while (!skyline.empty() && nv[skyline.top()] > nv[i]) {
prev[skyline.top()] = i + 1;
skyline.pop();
}
skyline.push(i);
}
while (!skyline.empty()) {
prev[skyline.top()] = 0;
skyline.pop();
}
int p = 0;
for (int i = 0; i < n; i ++) {
update(1, 0, n - 1, prev[i], i, nv[i]);
while (p < (int)vq.size() && vq[p].r == i) {
auto x = query(1, 0, n - 1, vq[p].l, vq[p].r);
if (x.mn + v[vq[p].l] - nv[vq[p].l] < 0)
ans[vq[p].pos] = -1;
else
ans[vq[p].pos] = sp[vq[p].r] - (vq[p].l == 0 ? 0 : sp[vq[p].l - 1]) - x.sum;
p ++;
}
}
for (int i = 0; i < q; i ++)
cout << ans[i] << '\n';
}
