#include <bits/stdc++.h>
/*
Checklist:
- Check statement:
- Check filename:
- Check test limit:
- Stresstest:
*/
using namespace std;
using ll = long long;
#define int long long
#define pii pair<ll, ll>
#define fi first
#define se second
const ll N = 5e5 + 5, inf = 1e18, mod = 1e9 + 7, block = 320, lim = 19;
int n, k;
int c[N], a[N];
int q;
pii qry[N];
int bad[N], pfs[N];
int L[N];
int up[N][lim + 1], t[N][lim + 1];
struct ST {
vector <int> st;
ST (int _n) {
st.assign(4 * (_n + 5), 0);
}
void build(int i, int l, int r) {
if (l == r) {
st[i] = a[l];
return;
}
int mid = (l + r) / 2;
build(2 * i, l, mid);
build(2 * i + 1, mid + 1, r);
st[i] = min(st[2 * i], st[2 * i + 1]);
}
int get(int i, int l, int r, int u, int v) {
if (u > r || v < l) return inf;
if (u <= l && r <= v) return st[i];
int mid = (l + r) / 2;
return min(get(2 * i, l, mid, u, v), get(2 * i + 1, mid + 1, r, u, v));
}
} st(N);
void preprocess() {
for (int i = 2; i <= n; i++) {
bad[i] = bad[i - 1];
if (c[i] % k < c[i - 1] % k) bad[i]++;
}
for (int i = 1; i <= n; i++) {
a[i] = c[i] - (c[i] % k + bad[i] * k);
pfs[i] = pfs[i - 1] + a[i];
}
st.build(1, 1, n);
stack<int> s;
for (int i = 1; i <= n; i++) {
while (!s.empty() && a[s.top()] > a[i]) s.pop();
L[i] = s.empty() ? 0 : s.top();
s.push(i);
up[i][0] = L[i];
t[i][0] = pfs[i] - pfs[L[i]] - (i - L[i]) * a[i];
}
for (int i = 1; i <= lim; i++) {
for (int j = 1; j <= n; j++) {
int mid = up[j][i - 1];
if (mid == 0) {
up[j][i] = 0;
t[j][i] = t[j][i - 1];
} else {
up[j][i] = up[mid][i - 1];
t[j][i] = t[j][i - 1] + t[mid][i - 1];
}
}
}
}
signed main() {
ios::sync_with_stdio(false);
cin.tie(0);
if (fopen(".inp", "r")) {
freopen(".inp", "r", stdin);
freopen(".out", "w", stdout);
}
cin >> n >> k;
for (int i = 1; i <= n; i++) cin >> c[i];
preprocess();
cin >> q;
for (int i = 1; i <= q; i++) {
int l, r;
cin >> l >> r;
if (st.get(1, 1, n, l, r) + bad[l] * k < 0) {
cout << -1 << '\n';
continue;
}
int sum = 0;
int cur = r;
for (int j = lim; j >= 0; j--) {
if (cur == 0) break;
if (up[cur][j] != 0 && up[cur][j] >= l) {
sum += t[cur][j];
cur = up[cur][j];
}
}
if (cur != 0 && cur >= l) {
sum += pfs[cur] - pfs[l - 1] - (cur - l + 1) * a[cur];
}
cout << sum / k << '\n';
}
return 0;
}
