// JOI 2024 (Fish 3)
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define fi first
#define se second
#define ins insert
#define eb emplace_back
void sol()
{
int n, d;
cin >> n >> d;
vector<int> a(n + 1);
for(int i=0;i<n;i++) cin >> a[i];
vector<int> cur(n + 1), actreq(n + 1), req(n + 1), preq(n + 1);
int ofs = 0;
for(int i=1;i<=n;i++) {
cur[i] = cur[i - 1] + ((d + (a[i] % d) - (cur[i-1] % d)) %d);
req[i] = actreq[i] = (a[i] - cur[i]) / d;
ofs = min(ofs, actreq[i]);
}
ofs = - ofs;
for(int i=1;i<=n;i++) req[i] += ofs;
for(int i=1;i<=n;i++) preq[i] = req[i] + preq[i - 1];
vector<vector<int>> li(n + 1, vector<int>(19));
vector<vector<int>> lis(n + 1, vector<int>(19));
{
stack<pair<int,int>> s;
s.emplace(0,0);
for(int i=1;i<=n;i++) {
while(s.top().fi > req[i]) s.pop();
li[i][0] = s.top().se;
lis[i][0] = req[i] * (i - s.top().se);
s.emplace(req[i], i);
}
for(int j=1;j<=18;j++) {
for(int i=1;i<=n;i++) {
li[i][j] = li[li[i][j - 1]][j - 1];
lis[i][j] = lis[li[i][j - 1]][j - 1] + lis[i][j - 1];
}
}
}
int q;
cin >> q;
for(int i=1;i<=q;i++) {
int l ,r;
cin >> l >> r;
int ans = preq[r] - preq[l - 1];
for(int j=18;j>=0;j--) {
if(li[r][j] >= l){
ans -= lis[r][j];
r = li[r][j];
}
}
ans -= req[r] * (r - l + 1);
if(actreq[r] + cur[l] / d >= 0) cout << ans << '\n';
else cout << "-1" << '\n';
}
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(0);
sol();
return 0;
}
