#include<bits/stdc++.h>
using namespace std;
#define int long long
struct Node{
int val, lazy;
Node (int _val=0){
val=_val, lazy=LLONG_MAX;
}
Node operator+(const Node &b){
return Node(val+b.val);
}
};
struct SegmentTree{
int n;
vector<Node> t;
void init(int _n){
n=_n;
t.assign(4*n+1, Node());
}
void apply(int k, int l, int r, int val){
t[k].val=val*(r-l+1);
t[k].lazy=val;
}
void push(int k, int l, int r){
if (t[k].lazy!=LLONG_MAX){
int mid=(l+r)>>1;
apply(k<<1, l, mid, t[k].lazy);
apply(k<<1|1, mid+1, r, t[k].lazy);
t[k].lazy=LLONG_MAX;
}
}
void update(int k, int l, int r, int L, int R, int val){
if (r<L || R<l) return;
if (L<=l && r<=R){
apply(k, l, r, val);
return;
}
push(k, l, r);
int mid=(l+r)>>1;
update(k<<1, l, mid, L, R, val);
update(k<<1|1, mid+1, r, L, R, val);
t[k]=t[k<<1]+t[k<<1|1];
}
Node get(int k, int l, int r, int L, int R){
if (r<L || R<l) return t[0];
if (L<=l && r<=R) return t[k];
push(k, l, r);
int mid=(l+r)>>1;
return get(k<<1, l, mid, L, R)+get(k<<1|1, mid+1, r, L, R);
}
} seg;
const int N=3e5+10, LG=19;
int n, d, a[N], b[N], cnt[N], pf[N], ans[N], sp[LG][N], pfc[N];
vector<pair<int, int>> v[N];
int32_t main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n >> d;
for (int i=1; i<=n; ++i) cin >> a[i], b[i]=a[i];
for (int i=1, sum=0; i<=n; ++i){
b[i]-=sum;
int mod=(b[i]%d+d)%d;
b[i]-=mod;
sum+=mod;
cnt[i]=mod;
sp[0][i]=b[i];
b[i]/=d;
}
for (int k=1; k<LG; ++k) for (int i=1; i+(1<<k)-1<=n; ++i) sp[k][i]=min(sp[k-1][i], sp[k-1][i+(1<<(k-1))]);
partial_sum(b, b+n+1, pf);
partial_sum(cnt, cnt+n+1, pfc);
seg.init(n);
int q; cin >> q;
for (int i=1; i<=q; ++i){
int l, r; cin >> l >> r;
v[r].emplace_back(l, i);
}
stack<int> st;
for (int i=1; i<=n; ++i){
while (st.size() && b[i]<=b[st.top()]) st.pop();
seg.update(1, 1, n, st.empty()?1:st.top()+1, i, b[i]);
st.push(i);
for (auto &j:v[i]){
int l=j.first, id=j.second, r=i;
if (l==r){
ans[id]=0;
continue;
}
int lg=__lg(r-l);
int cnt_l=a[l]%d;
int min_val=min(sp[lg][l+1], sp[lg][r-(1<<lg)+1]);
if (min_val+pfc[l]<cnt_l) ans[id]=-1;
else{
int b_l=(a[l]-cnt_l)/d;
ans[id]=pf[r]-pf[l]-seg.get(1, 1, n, l+1, r).val+b_l-min(b_l, (min_val+pfc[l]-cnt_l)/d);
}
}
}
for (int i=1; i<=q; ++i) cout << ans[i] << '\n';
return 0;
}
