#include <bits/stdc++.h>
using namespace std;
#define int long long
const int mxn = 3e5 + 5;
int n, d;
int a[mxn], pfx[mxn], bad[mxn], seg[4 * mxn];
pair<int, int> up[mxn][20];
vector<pair<int, int>> tmp;
int sum(int l, int r) {
if (r < l) return (int)0;
return pfx[r] - pfx[l - 1];
}
int pre[mxn];
void buildpre() {
sort(tmp.begin(), tmp.end());
set<int> add;
for (auto &x : tmp) {
int v = x.first, i = x.second;
if (!add.size()) {
pre[i] = (int)0;
add.insert(-i);
continue;
}
if (-*add.rbegin() > i) {
pre[i] = (int)0;
add.insert(-i);
continue;
}
pre[i] = -(*add.lower_bound(-i));
add.insert(-i);
}
}
void buildst(int x, int l, int r) {
if (l == r) {
seg[x] = a[l];
return;
}
int mid = (l + r) / 2;
buildst(x * 2, l, mid);
buildst(x * 2 + 1, mid + 1, r);
seg[x] = min(seg[x * 2], seg[x * 2 + 1]);
}
int queryst(int x, int l, int r, int ql, int qr) {
if (r < ql || qr < l) return 1e18;
if (ql <= l && r <= qr) return seg[x];
int mid = (l + r) / 2;
return min(queryst(x * 2, l, mid, ql, qr), queryst(x * 2 + 1, mid + 1, r, ql, qr));
}
signed main() {
cout.tie(nullptr); cin.tie(nullptr); ios::sync_with_stdio(false);
cin >> n >> d;
for (int i = 1; i <= n; i++) cin >> a[i];
for (int i = 2; i <= n; i++) if ((a[i] % d) < (a[i - 1] % d)) bad[i]++;
for (int i = 2; i <= n; i++) bad[i] += bad[i - 1];
for (int i = 1; i <= n; i++) a[i] -= (a[i] % d + bad[i] * d);
for (int i = 1; i <= n; i++) pfx[i] = pfx[i - 1] + a[i];
for (int i = 1; i <= n; i++) tmp.push_back({a[i], i});
buildpre(); buildst(1, 1, n);
for (int i = 1; i <= n; i++) up[i][0] = {pre[i], sum(pre[i] + 1, i) - (i - pre[i]) * a[i]};
for (int j = 1; j < 20; j++) {
for (int i = 1; i <= n; i++) {
up[i][j] = {up[up[i][j - 1].first][j - 1].first, up[i][j - 1].second + up[up[i][j - 1].first][j - 1].second};
}
}
int q; cin >> q;
while (q--) {
int l, r;
cin >> l >> r;
if (queryst(1, 1, n, l, r) + bad[l] * d < 0) {
cout << "-1\n";
continue;
}
int sm = 0; int curr = r;
for (int i = 19; i >= 0; i--) {
if (up[curr][i].first >= l) {
sm += up[curr][i].second;
curr = up[curr][i].first;
}
}
sm += sum(l, curr) - (curr - l + 1) * a[curr];
cout << sm/d << '\n';
}
}
