#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pll pair<long long, long long>
#define pb push_back
#define F first
#define S second
#define all(x) (x).begin(), (x).end()
const ll N = 3e5 + 100;
const ll inf = 1e18;
const ll mod = 1e9 + 7;
const ll blocks = 350;
ll n,d,q;
ll a[N], res[N];
vector<pll>t[N];
struct segment_tree{
ll n;
vector<ll>st, lz;
void init(ll _n){
n = _n;
st.clear(); st.resize(4 * n + 10, 0);
lz.clear(); lz.resize(4 * n + 10, 0);
}
void down(ll id, ll l, ll r){
st[id] += lz[id] * (r - l + 1);
if(l != r) lz[2 * id] += lz[id], lz[2 * id + 1] += lz[id];
lz[id] = 0;
}
void update(ll id, ll l, ll r, ll left, ll right, ll val){
down(id, l, r);
if(l > right || r < left) return;
if(left <= l && r <= right){
lz[id] += val;
down(id, l, r);
return;
}
ll mid = (l + r) / 2;
update(2 * id, l, mid, left, right, val);
update(2 * id + 1, mid + 1, r, left, right, val);
st[id] = (st[2 * id] + st[2 * id + 1]);
}
ll get(ll id, ll l, ll r, ll left, ll right){
down(id, l, r);
if(l > right || r < left) return 0;
if(left <= l && r <= right) return st[id];
ll mid = (l + r) / 2;
return get(2 * id, l, mid, left, right) + get(2 * id + 1, mid + 1, r, left, right);
}
void update(ll l, ll r, ll val){update(1,1,n,l,r,val);}
ll get(ll l, ll r){return get(1,1,n,l,r);}
} st;
ll get(ll pos){return a[pos] - st.get(pos, pos) * d;}
void to_thic_cau(){
cin >> n >> d;
for(int i = 1; i <= n;i++) cin >> a[i];
cin >> q;
for(int i = 1; i <= q;i++){
ll l,r; cin >> l >> r;
t[r].pb({l, i});
}
st.init(n);
stack<ll>s;
for(int i = 1; i <= n;i++){
ll r = i;
while(s.size()){
ll l = s.top(), x = get(r - 1), y = get(r);
if(x <= y) break;
st.update(l, r - 1, (x - y) / d + ((x - y) % d != 0));
r = l; s.pop();
}
s.push(r);
for(auto x : t[i]) res[x.S] = (get(x.F) < 0 ? -1 : st.get(x.F, i));
}
for(int i = 1; i <= q;i++) cout << res[i] << ' ';
cout << '\n';
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
ll tc = 1;
//cin >> tc;
while(tc--) to_thic_cau();
}
