#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
#define fi first
#define se second
#define vi vector<int>
#define vll vector<long long>
#define pii pair<int, int>
#define pll pair<long long, long long>
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
mt19937_64 rng64(chrono::high_resolution_clock::now().time_since_epoch().count());
inline int rand(int l,int r){return uniform_int_distribution<int>(l, r)(rng);}
inline ll rand(ll l,ll r){return uniform_int_distribution<ll>(l, r)(rng64);}
#ifdef DEBUG
auto&operator<<(auto&o,pair<auto,auto>p){return o<<"("<<p.first<<", "<<p.second<<")";}
auto operator<<(auto&o,auto x)->decltype(x.end(),o){o<<"{";int i=0;for(auto e:x)o<<","+!i++<<e;return o<<"}";}
#define debug(X...)cerr<<"["#X"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(X)
#else
#define debug(...){}
#endif
struct custom_hash {
static uint64_t splitmix64(uint64_t x) {
x += 0x9e3779b97f4a7c15;
x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
return x ^ (x >> 31);
}
size_t operator()(uint64_t x) const {
static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
return splitmix64(x + FIXED_RANDOM);
}
};
struct pair_hash{
size_t operator()(const pair<int,int>&x)const{
return hash<long long>()(((long long)x.first)^(((long long)x.second)<<32));
}
};
const int MAXN = 3e5 + 7;
ll A[MAXN];
ll ans[MAXN];
vector<pii> queries[MAXN];
ll val[MAXN];
ll prefCnt[MAXN];
ll pref[MAXN];
ll n, q, D;
int main(){
ios_base::sync_with_stdio(0);
cin.tie(NULL);
cout.tie(NULL);
cin >> n >> D;
for(int i = 1; i <= n; i++){
cin >> A[i];
}
cin >> q;
for(int i = 1; i <= q; i++){
int l, r;
cin >> l >> r;
queries[r].pb(mp(l, i));
}
for(int i = 2; i <= n; i++){
prefCnt[i] = prefCnt[i - 1];
if((A[i] % D) < (A[i - 1] % D)){
prefCnt[i]++;
}
}
for(int i = 1; i <= n; i++){
pref[i] = pref[i - 1];
val[i] = (ll)((ll)A[i] - (A[i] % D) - D * prefCnt[i]) / D;
pref[i] = (ll)pref[i] + val[i];
}
vector<pair<int, ll>> vec = {};
for(int i = 1; i <= n; i++){
while(sz(vec) && val[i] <= val[vec.back().fi]){
vec.pop_back();
}
ll add = 0LL;
if(sz(vec) == 0){
add = (ll)(pref[i - 1] - val[i] * (i - 1));
}else{
add = vec.back().se + (ll)(pref[i - 1] - pref[vec.back().fi] - val[i] * (i - vec.back().fi - 1));
}
vec.pb(mp(i, add));
for(auto [s, id] : queries[i]){
int l = 0;
int p = sz(vec) - 1;
int mid;
while(l < p){
mid = (l + p) / 2;
if(vec[mid].fi >= s){
p = mid;
}else{
l = mid + 1;
}
}
if((ll)val[vec[l].fi] + prefCnt[s] < 0LL){
ans[id] = -1LL;
continue;
}
int g = (l == 0 ? 1 : vec[l - 1].fi + 1);
ans[id] = vec.back().se - (l > 0 ? vec[l - 1].se : 0LL);
if(g < s){
ans[id] = (ll)ans[id] - (ll)(pref[s - 1] - pref[g - 1] - val[vec[l].fi] * (s - g));
}
}
}
for(int i = 1; i <= q; i++){
cout << ans[i] << '\n';
}
return 0;
}
