#include<bits/stdc++.h>
#define int long long
#define pb push_back
#define fi first
#define se second
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int maxN = 1e6 + 5;
const int mod = 1e9 + 7;
const ll oo = 1e18;
int n, d, q;
int a[maxN];
vector<pair<int, int>> query[maxN];
int sum[maxN];
int res[maxN];
void ReadInput()
{
cin >> n >> d;
for(int i=1; i<=n; i++)
{
cin >> a[i];
sum[i] = sum[i - 1] + a[i];
}
cin >> q;
for(int i=1; i<=q; i++)
{
int l, r;
cin >> l >> r;
query[r].pb({l, i});
}
}
struct LazySegtree
{
vector<int> st, lazy;
void init(int n)
{
st.resize(4 * n + 5, 0);
lazy.resize(4 * n + 5, 0);
}
void down(int id, int l, int r)
{
int t = lazy[id];
int mid = (l + r) / 2;
st[id * 2] += t * (mid - l + 1);
st[id * 2 + 1] += t * (r - mid);
lazy[id * 2] += t;
lazy[id * 2 + 1] += t;
lazy[id] = 0;
}
void update(int id, int l, int r, int pos, int val)
{
if(l > pos | r < pos) return;
if(l == r && l == pos)
{
st[id] = val;
return;
}
down(id, l, r);
int mid = (l + r) / 2;
update(id * 2, l, mid, pos, val);
update(id * 2 + 1, mid + 1, r, pos, val);
st[id] = st[id * 2] + st[id * 2 + 1];
}
void range_upd(int id, int l, int r, int u, int v, int val)
{
if(l > v || r < u) return;
if(l >= u && r <= v)
{
st[id] += val * (r - l + 1);
lazy[id] += val;
return;
}
int mid = (l + r) / 2;
down(id, l, r);
range_upd(id * 2, l, mid, u, v, val);
range_upd(id * 2 + 1, mid + 1, r, u, v, val);
st[id] = st[id * 2] + st[id * 2 + 1];
}
int get(int id, int l, int r, int u, int v)
{
if(l > v || r < u) return 0;
if(l >= u && r <= v) return st[id];
int mid = (l + r) / 2;
down(id, l, r);
return get(id * 2, l, mid, u, v) + get(id * 2 + 1, mid + 1, r, u, v);
}
};
void Solve()
{
LazySegtree tree;
tree.init(n);
for(int i=1; i<=n; i++)
{
tree.update(1, 1, n, i, a[i]);
int val = tree.get(1, 1, n, i - 1, i - 1);
if(val > a[i])
{
int t = (val - a[i] - 1) / d + 1;
tree.range_upd(1, 1, n, 1, i - 1, -d * t);
}
for(auto [l, id] : query[i])
{
if(tree.get(1, 1, n, l, l) < 0) res[id] = -1;
else res[id] = (sum[i] - sum[l - 1] - tree.get(1, 1, n, l, i)) / d;
}
}
for(int i=1; i<=q; i++)
cout << res[i] << '\n';
}
#define taskname "sol"
int32_t main()
{
if (fopen(taskname ".inp", "r"))
{
freopen(taskname ".inp", "r", stdin);
//freopen(taskname ".out", "w", stdout);
}
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int T = 1;
//cin >> T;
for(int itest=1; itest<=T; itest++)
{
ReadInput();
Solve();
}
}
