#include <bits/stdc++.h>
using namespace std;
using lint = long long;
using pi = array<lint, 2>;
#define sz(v) ((int)(v).size())
#define all(v) (v).begin(), (v).end()
#define cr(v, n) (v).clear(), (v).resize(n);
const int MAXN = 300005;
int par[20][MAXN];
lint dep[MAXN];
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
lint n, d;
cin >> n >> d;
vector<lint> a(n), sum(n + 1), dum(n), g(n);
for (auto &x : a)
cin >> x;
for (int i = 0; i + 1 < n; i++) {
dum[i + 1] = dum[i] + (a[i + 1] % d < a[i] % d);
}
for (int i = 0; i < n; i++) {
sum[i + 1] = sum[i] + a[i] / d - dum[i];
g[i] = a[i] / d - dum[i];
}
vector<int> stk = {-1};
for (int i = 0; i < n; i++) {
while (sz(stk) > 1 && g[stk.back()] >= g[i])
stk.pop_back();
par[0][i + 1] = stk.back() + 1;
dep[i + 1] = dep[stk.back() + 1] + (i - stk.back()) * g[i];
stk.push_back(i);
}
for (int i = 1; i < 20; i++) {
for (int j = 1; j <= n; j++) {
par[i][j] = par[i - 1][par[i - 1][j]];
}
}
int q;
cin >> q;
while (q--) {
int l, r;
cin >> l >> r;
l--;
int lup = r;
for (int i = 19; i >= 0; i--) {
if (par[i][lup] > l)
lup = par[i][lup];
}
lint moksum = dep[r] - dep[lup] + (lup - l) * g[lup - 1];
lint opt = g[lup - 1];
if (opt + dum[l] < 0)
cout << "-1\n";
else
cout << sum[r] - sum[l] - moksum << "\n";
}
}
