#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<long long, long long>;
#define pb push_back
#define ins insert
#define fi first
#define se second
#define btpc __builtin_popcount
#define btclz __builtin_clz
#define sz(x) (int)(x.size());
#define all(x) x.begin(), x.end()
#define debug(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int d4x[4] = {1, 0, -1, 0}; int d4y[4] = {0, 1, 0, -1};
int d8x[8] = {0, 1, 1, 1, 0, -1, -1, -1};
int d8y[8] = {1, 1, 0, -1, -1, -1, 0, 1};
template<class X, class Y>
bool minimize(X &x, const Y &y) {
if (x > y)
{
x = y;
return true;
}
return false;
}
template<class X, class Y>
bool maximize(X &x, const Y &y) {
if (x < y)
{
x = y;
return true;
}
return false;
}
const int MOD = 1e9 + 7; //998244353
/* Author : Le Ngoc Bao Anh, A5K37 Le Quy Don High School for Gifted Student, Da Nang */
/* University of Wollongong */
const long long INF = 1e9;
const int N = 3e5 + 10;
struct SegmentTree {
struct Node {
int lazy;
ll sum;
int size;
Node() {
lazy = -1;
sum = size = 0;
}
};
vector<Node> node;
int n;
SegmentTree(int _n = 0) {
n = _n;
node.resize(4 * n + 7);
for(int i = 1; i <= 4 * n; i++) node[i] = Node();
build(1, n, 1);
}
void build(int l, int r, int id) {
node[id].size = r - l + 1;
if(l == r) return;
int mid = (l + r) >> 1;
build(l, mid, id << 1);
build(mid + 1, r, id << 1 | 1);
}
void Down(int id) {
if(node[id].lazy == -1) return;
int cur = node[id].lazy;
node[id].lazy = -1;
for(int i = (id << 1); i <= (id << 1 | 1); i++) {
node[i].lazy = cur;
node[i].sum = 1ll * node[i].size * cur;
}
}
Node merge(const Node &a, const Node &b) const {
Node ans = Node();
ans.size = a.size + b.size;
ans.sum = a.sum + b.sum;
return ans;
};
void update(int lo, int hi, int l, int r, int id, int val) {
if(l > hi || r < lo) return;
if(lo <= l && r <= hi) {
node[id].sum = 1ll * node[id].size * val;
node[id].lazy = val;
return;
}
Down(id);
int mid = (l + r) >> 1;
update(lo, hi, l, mid, id << 1, val);
update(lo, hi, mid + 1, r, id << 1 | 1, val);
node[id] = merge(node[id << 1], node[id << 1 | 1]);
}
Node get(int lo, int hi, int l, int r, int id) {
if(l > hi || r < lo) return Node();
if(lo <= l && r <= hi) return node[id];
int mid = (l + r) >> 1;
Down(id);
Node left = get(lo, hi, l, mid, id << 1);
Node right = get(lo, hi, mid + 1, r, id << 1 | 1);
return merge(left, right);
}
void update(int l, int r, int x) {
update(l, r, 1, n, 1, x);
}
ll get(int l, int r) {
return get(l, r, 1, n, 1).sum;
}
};
ll A[N], C[N], dp[N], old[N];
ll pref[N], ans[N];
vector<pii> queries[N];
void BaoJiaoPisu() {
int n;
ll D; cin >> n >> D;
for(int i = 1; i <= n; i++) cin >> C[i];
for(int i = 1; i <= n; i++) {
A[i] = C[i] / D;
old[i] = A[i];
}
for(int i = 1; i < n; i++) {
if(C[i] % D > C[i + 1] % D) {
dp[i]++;
}
}
for(int i = n; i >= 1; i--) {
dp[i] += dp[i + 1];
A[i] += dp[i];
}
int q; cin >> q;
for(int i = 1; i <= q; i++) {
int l, r; cin >> l >> r;
queries[r].pb({l, i});
}
SegmentTree IT = SegmentTree(n);
for(int i = 1; i <= n; i++) {
pref[i] = pref[i - 1] + A[i];
}
for(int i = 1; i <= n; i++) {
int l = 1, r = i - 1, pos = i;
while(l <= r) {
int mid = (l + r) >> 1;
if(IT.get(mid, mid) > A[i]) {
pos = mid;
r = mid - 1;
} else {
l = mid + 1;
}
}
IT.update(pos, i, A[i]);
for(auto cur : queries[i]) {
int l = cur.fi;
int id = cur.se;
ans[id] = (pref[i] - pref[l - 1]) - IT.get(l, i);
if(old[l] < A[l] - IT.get(l, l)) ans[id] = -1;
}
}
for(int i = 1; i <= q; i++) {
cout << ans[i] << '\n';
}
}
int main()
{
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#ifndef ONLINE_JUDGE
#else
//online
#endif
int tc = 1, ddd = 0;
// cin >> tc;
while(tc--) {
//ddd++;
//cout << "Case #" << ddd << ": ";
BaoJiaoPisu();
}
}
