#include <bits/stdc++.h>
using namespace std;
mt19937_64 rng(time(0));
using ll = long long;
#define int long long
const int N = 2e5 + 1;
void solve() {
int n, d; cin >> n >> d;
vector<int> c(n + 1), pref (n + 1), a(n + 1), b(n + 1);
vector<int>p2(n + 1);
vector<int>p3(n + 1);
vector<int>p4(n + 1);
for (int i = 1; i <= n; ++i) {
cin >> c[i];
a[i] = c[i] / d;
b[i] = c[i] % d;
pref[i] = pref[i - 1] + c[i];
p2[i] = p2[i - 1] + a[i];
}
for (int i = 1; i < n; ++i) {
p3[i] = p3[i - 1] + bool (b[i] > b[i + 1]);
p4[i] = p4[i - 1] + (b[i] > b[i + 1] ? i : 0);
}
int q; cin >> q;
vector<int> id(n + 1);
for (int i = 1; i <= n; ++i) {
int nw = a[i];
for (int j = i - 1; j >= 1; j -= 1) {
if (a[j] >= nw) {
if (b[j] > b[j + 1]) nw -= 1;
} else {
id[i] = j;
break;
}
}
}
vector<vector<int>> W (20, vector<int> (n + 1));
vector<vector<int>> binup (20, vector<int> (n + 1));
vector<vector<int>> cost (20, vector<int> (n + 1));
for (int i = n; i >= 1; --i) {
binup[0][i] = id[i];
int ps = id[i] + 1, r = i;
int ans = p2[r - 1] - p2[ps - 1];
ans -= a[r] * (r - ps);
int all = p4[r - 1] - p4[ps - 1];
int cnt = p3[r - 1] - p3[ps - 1];
ans += all - (ps - 1) * cnt;
W[0][i] += cnt;
cost[0][i] += ans;
}
for (int j = 1; j < 20; ++j) {
for (int i = 1; i <= n; ++i) {
binup[j][i] = binup[j - 1][binup[j - 1][i]];
cost[j][i] = cost[j - 1][i] + cost[j - 1][binup[j - 1][i]];
W[j][i] = W[j - 1][i] + W[j - 1][binup[j - 1][i]];
}
}
while (q--) {
int l, r; cin >> l >> r;
int v = r;
int ans = 0;
int mn = a[r];
for (int pw = 19; pw >= 0; --pw) {
if (binup[pw][v] > l) {
ans += cost[pw][v];
mn -= W[pw][v];
v = binup[pw][v];
}
}
int ps = max (id[v] + 1, l);
ans += p2[v - 1] - p2[ps - 1];
ans -= a[v] * (v - ps);
int all = p4[v - 1] - p4[ps - 1];
int cnt = p3[v - 1] - p3[ps - 1];
ans += all - (ps - 1) * cnt;
mn -= cnt;
if (mn < 0) {
cout << "-1\n";
continue;
}
cout << ans << '\n';
}
}
int32_t main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
#ifdef LOCAL
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif // LOCAL
int T = 1;
while (T--) solve();
return 0;
}
