#include<bits/stdc++.h>
using namespace std;
#define foru(i,a,b) for(int i=(a); i<=(b); ++i)
#define ford(i,a,b) for(int i=(a); i>=(b); --i)
#define rep(i,a) for(int i=0; i<(a); ++i)
#define sz(a) (int)(a).size()
#define all(a) (a).begin(),(a).end()
#define bit(s,i) (((s)>>(i))&1)
#define ii pair<int,int>
#define vi vector<int>
#define vii vector<ii>
#define fi first
#define se second
#define ll long long
#define eb emplace_back
#define pb push_back
#define __builtin_popcount __builtin_popcountll
#define _ << " " <<
template <class X, class Y> bool maxi(X &x, Y y){return x<y?x=y,true:false;}
template <class X, class Y> bool mini(X &x, Y y){return x>y?x=y,true:false;}
const int N=3e5+5;
int n,q; ll d,c[N],ans[N];
vector<ii> que[N];
int stk[N],top;
#define lc id<<1
#define rc id<<1|1
ll st[N<<2],lz[N<<2];
void apply(int id, int len, ll val){
lz[id]+=val;
st[id]+=val*len;
}
void down(int id, int len1, int len2){
if(lz[id]==0) return;
apply(lc,len1,lz[id]);
apply(rc,len2,lz[id]);
lz[id]=0;
}
void upd(int u, int v, ll val, int id=1, int l=1, int r=n){
if(u>r||v<l) return;
if(u<=l&&r<=v){
apply(id,r-l+1,val);
return;
}
int mid=(l+r)>>1;
down(id,mid-l+1,r-mid);
upd(u,v,val,lc,l,mid);
upd(u,v,val,rc,mid+1,r);
st[id]=st[lc]+st[rc];
}
ll get(int u, int v, int id=1, int l=1, int r=n){
if(u>r||v<l) return 0;
if(u<=l&&r<=v) return st[id];
int mid=(l+r)>>1;
down(id,mid-l+1,r-mid);
return get(u,v,lc,l,mid)+get(u,v,rc,mid+1,r);
}
void solve(){
cin>>n>>d;
foru(i,1,n) cin>>c[i];
cin>>q;
foru(i,1,q){
int l,r; cin>>l>>r;
que[r].eb(l,i);
}
foru(i,1,n){
auto cur=[&](int x)->ll{
return c[x]-1LL*get(x,x)*d;
};
while(top && cur(stk[top])>cur(stk[top]+1)){
ll dec=(cur(stk[top])-cur(stk[top]+1)+d-1)/d;
// cout<<(cur(stk[top])- cur(stk[top]+1)+d-1)/d _ dec<<'\n';
upd(stk[top-1]+1, stk[top], dec);
// cout<<stk[top-1]+1 _ stk[top] _ dec _ i<<'\n';
--top;
}
stk[++top]=i;
for(auto [l,id]:que[i]){
if(cur(l)>=0) ans[id]=get(l,i);//,cout<<l _ i _ get(l,i)<<'\n';
else ans[id]=-1;
}
}
foru(i,1,q) cout<<ans[i]<<'\n';
}
int32_t main(){
#define task "test"
if(fopen(task".inp", "r")){
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
cin.tie(0)->sync_with_stdio(0);
int tc=1; //cin>>tc;
foru(i,1,tc){
solve();
}
}
