#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include <D:/debug.h>
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif
#define fi first
#define se second
#define pii pair<int,int>
#define pll pair<long long,long long>
#define int long long
const int N = 3e5 + 5, mod = 1e9 + 7, imod = (mod + 1) / 2;
const long long inf = 1e18;
int n, a[N], d,q;
int seg[4*N],lazy[4*N];
void down(int crr,int l,int r){
if(lazy[crr]){
const int x=lazy[crr],mid=l+r>>1; lazy[crr]=0;
lazy[crr*2]+=x; lazy[crr*2+1]+=x;
seg[crr*2]+=x*(mid-l+1); seg[crr*2+1]+=x*(r-mid);
}
}
void upd(int crr,int l,int r,int lm,int rm,int val){
if(l>rm || lm>r) return;
if(lm<=l && r<=rm){
seg[crr]+=val*(r-l+1);
lazy[crr]+=val;
return;
}
down(crr,l,r);
int mid=(l+r)>>1;
upd(crr*2,l,mid,lm,rm,val);
upd(crr*2+1,mid+1,r,lm,rm,val);
seg[crr]=seg[crr*2]+seg[crr*2+1];
}
int get(int crr,int l,int r,int lm,int rm){
if(l>rm || lm>r) return 0;
if(lm<=l && r<=rm) return seg[crr];
down(crr,l,r);
int mid=(l+r)>>1;
return get(crr*2,l,mid,lm,rm)+get(crr*2+1,mid+1,r,lm,rm);
}
int ans[N];
vector<pii> event[N];
int solve(int u){
return a[u]-get(1,1,n,u,u)*d;
}
signed main(){
//freopen("GAME.inp","r",stdin);
//freopen("MESSAGE.out","w",stdout);
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
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;
event[r].push_back({l,i});
}
vector<int> st;
for(int i=1;i<=n;i++){
int r=i;
while(!st.empty()){
int l=st.back();
int x=solve(r-1),y=solve(r);
if(x<=y) break;
upd(1,1,n,l,r-1,(x-y+d-1)/d);
r=l;
st.pop_back();
}
st.push_back(r);
for(const pii j:event[i]){
if(solve(j.fi)<0) ans[j.se]=-1;
else ans[j.se]=get(1,1,n,j.fi,i);
}
}
for(int i=1;i<=q;i++){
cout<<ans[i]<<"\n";
}
}
