// Hallelujah, praise the one who set me free
// Hallelujah, death has lost its grip on me
// You have broken every chain, There's salvation in your name
// Jesus Christ, my living hope
#include <bits/stdc++.h>
using namespace std;
#define REP(i, s, e) for (int i = (s); i < (e); i++)
#define RREP(i, s, e) for (int i = (s); i >= (e); i--)
template <class T>
inline bool mnto(T& a, T b) {return a > b ? a = b, 1 : 0;}
template <class T>
inline bool mxto(T& a, T b) {return a < b ? a = b, 1: 0;}
typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
typedef tuple<int, int, int> iii;
#define ALL(_a) _a.begin(), _a.end()
#define SZ(_a) (int) _a.size()
#define pb push_back
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;
typedef vector<iii> viii;
#ifndef DEBUG
#define cerr if (0) cerr
#endif
const int INF = 1000000005;
const ll LINF = 1000000000000000005ll;
const int MAXN = 300005;
struct Block {
int l, r;
ll lc, rc;
};
int n;
ll d;
ll c[MAXN];
int q;
vii rl[MAXN];
ll ans[MAXN];
vector<Block> stk;
#define MLR int mid = lo + hi >> 1, lc = u << 1, rc = u << 1 ^ 1
ll sm[MAXN * 4], lz[MAXN * 4];
void apply(int u, int lo, int hi, ll x) {
lz[u] += x;
sm[u] += x * (hi - lo + 1);
}
void propo(int u, int lo, int hi) {
if (lz[u] == 0) {
return;
}
MLR;
apply(lc, lo, mid, lz[u]);
apply(rc, mid + 1, hi, lz[u]);
lz[u] = 0;
}
void incre(int s, int e, ll x, int u = 1, int lo = 1, int hi = n) {
if (lo >= s && hi <= e) {
apply(u, lo, hi, x);
return;
}
MLR;
propo(u, lo, hi);
if (s <= mid) {
incre(s, e, x, lc, lo, mid);
}
if (e > mid) {
incre(s, e, x, rc, mid + 1, hi);
}
sm[u] = sm[lc] + sm[rc];
}
ll qsm(int s, int e, int u = 1, int lo = 1, int hi = n) {
if (lo >= s && hi <= e) {
return sm[u];
}
MLR;
propo(u, lo, hi);
ll res = 0;
if (s <= mid) {
res += qsm(s, e, lc, lo, mid);
}
if (e > mid) {
res += qsm(s, e, rc, mid + 1, hi);
}
return res;
}
int main() {
#ifndef DEBUG
ios::sync_with_stdio(0), cin.tie(0);
#endif
cin >> n >> d;
REP (i, 1, n + 1) {
cin >> c[i];
}
cin >> q;
REP (i, 0, q) {
int l, r; cin >> l >> r;
rl[r].pb({l, i});
}
REP (i, 1, n + 1) {
while (!stk.empty() && stk.back().rc > c[i]) {
auto [l, r, lc, rc] = stk.back(); stk.pop_back();
ll w = (rc - c[i] - 1 + d) / d;
// lc - w * d >= stk.back().rc
// w <= (lc - stk.back().rc) / d
if (!stk.empty()) {
mnto(w, (lc - stk.back().rc) / d);
}
lc -= w * d; rc -= w * d;
incre(l, r, w);
if (!stk.empty() && lc - stk.back().rc < d) {
l = stk.back().l; lc = stk.back().lc;
stk.pop_back();
}
stk.pb({l, r, lc, rc});
}
stk.pb({i, i, c[i], c[i]});
for (auto [l, id] : rl[i]) {
ans[id] = qsm(l, i);
if (c[l] - qsm(l, l) * d < 0) {
ans[id] = -1;
}
}
}
REP (i, 0, q) {
cout << ans[i] << '\n';
}
return 0;
}
