#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pl;
typedef pair<int,int> pii;
typedef tuple<int,int,int> tt;
#define all(a) a.begin(), a.end()
#define filter(a) a.erase(unique(all(a)), a.end())
struct IT {
vector<ll> tr, lazy, lo;
vector<int> vec;
IT (int sz) : tr(4 * sz), lazy(4 * sz), lo(4 * sz) {}
ll getSum (int k, int l, int r) {
return tr[k] + ll(r - l + 1) * lazy[k];
}
ll getLo (int k) {
return lo[k] + lazy[k];
}
void refine (int k, int l, int r, int mid) {
lo[k] = min(getLo(2 * k), getLo(2 * k + 1));
tr[k] = getSum(2 * k, l, mid) + getSum(2 * k + 1, mid + 1, r);
}
void pushDown (int k, int l, int r, int mid) {
lazy[2 * k] += lazy[k], lazy[2 * k + 1] += lazy[k], lazy[k] = 0;
refine(k, l, r, mid);
}
void update (int a, int b, ll val, int k, int l, int r) {
if (b < l || r < a) return;
if (a <= l && r <= b) {
lazy[k] += val;
return;
}
int mid = (l + r) >> 1;
pushDown(k, l, r, mid);
update(a, b, val, 2 * k, l, mid);
update(a, b, val, 2 * k + 1, mid + 1, r);
refine(k, l, r, mid);
}
ll querySum (int a, int b, int k, int l, int r) {
if (b < l || r < a) return 0;
if (a <= l && r <= b) return getSum(k, l, r);
int mid = (l + r) >> 1;
pushDown(k, l, r, mid);
return querySum(a, b, 2 * k, l, mid) + querySum(a, b, 2 * k + 1, mid + 1, r);
}
ll queryLo (int a, int b, int k, int l, int r) {
if (b < l || r < a) return LLONG_MAX;
if (a <= l && r <= b) return getLo(k);
int mid = (l + r) >> 1;
pushDown(k, l, r, mid);
return min(queryLo(a, b, 2 * k, l, mid), queryLo(a, b, 2 * k + 1, mid + 1, r));
}
void walk (int a, int b, int k, int l, int r) {
if (b < l || r < a || getLo(k) > 0) return;
if (l == r) {
vec.push_back(l);
return;
}
int mid = (l + r) >> 1;
pushDown(k, l, r, mid);
walk(a, b, 2 * k, l, mid);
walk(a, b, 2 * k + 1, mid + 1, r);
}
vector<int> findZero (int a, int b, int k, int l, int r) {
vec.clear();
walk(a, b, k, l, r);
return vec;
}
};
const int mn = 3e5 + 5;
ll a[mn], base[mn], bound[mn], ans[mn];
vector<pii> qry[mn];
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
int n; ll D; cin >> n >> D;
for (int i = 1; i <= n; i++) {
cin >> a[i];
base[i] = a[i] % D, bound[i] = a[i] / D;
}
int q; cin >> q;
for (int i = 0; i < q; i++) {
int l, r; cin >> l >> r;
qry[r].push_back({l, i});
}
IT tree(n), cur(n);
ll last = LLONG_MAX;
priority_queue<int> pq; pq.push(0);
for (int i = n; i >= 1; i--) {
last = min(bound[i], last - (base[i] > base[i + 1]));
tree.update(i, i, bound[i] - last, 1, 1, n);
cur.update(i, i, last, 1, 1, n);
if (bound[i] == last) pq.push(i);
}
for (int i = n; i >= 1; i--) {
if (pq.top() == i) pq.pop();
ll decr = tree.queryLo(i, i, 1, 1, n);
while (decr) {
ll tmp = tree.queryLo(pq.top() + 1, i, 1, 1, n);
tree.update(pq.top() + 1, i, -tmp, 1, 1, n);
cur.update(pq.top() + 1, i, tmp, 1, 1, n);
if (pq.top() + 1 <= i - 1) {
vector<int> pos = tree.findZero(pq.top() + 1, i - 1, 1, 1, n);
for (int u : pos) pq.push(u);
}
decr -= tmp;
}
for (auto [l, id] : qry[i]) {
if (cur.queryLo(l, i, 1, 1, n) < 0) ans[id] = -1;
else ans[id] = tree.querySum(l, i, 1, 1, n);
}
}
for (int i = 0; i < q; i++) cout << ans[i] << "\n";
return 0;
}
