#include "bits/stdc++.h"
using namespace std;
#ifdef duc_debug
#include "bits/debug.h"
#else
#define debug(...)
#endif
const int maxn = 3e5 + 5;
const int LG = 19;
int n, q;
long long d, c[maxn];
long long prf[maxn], df[maxn];
long long ps[maxn];
long long st[maxn][LG + 1];
vector<int> g[maxn];
int pr[maxn], up[maxn][LG + 1];
long long dep[maxn];
void pre_dfs(int u) {
for (auto v : g[u]) {
up[v][0] = u;
for (int i = 1; i <= LG; ++i) {
up[v][i] = up[up[v][i - 1]][i - 1];
}
dep[v] = dep[u] + 1ll * (v - u) * (c[v] - prf[v]);
pre_dfs(v);
}
}
long long qry(int l, int r) {
int p = 31 - __builtin_clz(r - l + 1);
return min(st[l][p], st[r - (1 << p) + 1][p]);
}
void solve() {
cin >> n >> d;
for (int i = 1; i <= n; ++i) {
cin >> c[i];
}
for (int i = 1; i <= n; ++i) {
df[i] = (d + (c[i] % d) - (c[i - 1] % d)) % d;
prf[i] = prf[i - 1] + df[i];
ps[i] = ps[i - 1] + c[i] - prf[i];
st[i][0] = c[i] - prf[i];
}
for (int j = 1; j <= LG; ++j) {
for (int i = 1; i + (1 << j) <= n + 1; ++i) {
st[i][j] = min(st[i][j - 1], st[i + (1 << (j - 1))][j - 1]);
}
}
stack<int> st;
for (int i = 1; i <= n; ++i) {
while (!st.empty() and c[st.top()] - prf[st.top()] >= c[i] - prf[i]) st.pop();
pr[i] = (st.empty() ? 0 : st.top());
g[pr[i]].push_back(i);
st.push(i);
}
pre_dfs(0);
cin >> q;
while (q--) {
int l, r; cin >> l >> r;
long long offset = prf[l] - (c[l] % d);
if (qry(l, r) + offset < 0) {
cout << -1 << '\n';
continue;
}
int u = r;
long long res = 0;
for (int i = LG; i >= 0; --i) {
if (up[u][i] >= l) {
u = up[u][i];
}
}
res = dep[r] - dep[u] + 1ll * (c[u] - prf[u]) * (u - l + 1);
res = (ps[r] - ps[l - 1] - res);
cout << res / d << '\n';
}
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
solve();
return 0;
}
