#include <bits/stdc++.h>
using namespace std;
#define int long long
struct thing {
int l, r, val;
bool operator < (const thing &b) const {
if (l != b.l) return l < b.l;
if (r != b.r) return r < b.r;
return val < b.val;
}
};
const int maxn = 5e5 + 5, lg = 20, INF = 1e15;
int n, q, k;
int a[maxn], sum[maxn];
int b[200];
void ins(int l, int r, int val) {
for (int i=l;i<=r;i++) b[i] = val;
}
int qry(int i) {
return b[i];
}
pair<int,int> lift[maxn][lg];
signed main() {
ios::sync_with_stdio(0); cin.tie(0);
cin >> n >> q >> k;
for (int i=1;i<=n;i++) cin >> a[i];
if (n % 2 == 1) n++;
a[n] = k;
sum[0] = INF;
for (int i=1;i<=n;i++) {
if (i % 2 == 1) sum[i] = sum[i-1] + a[i];
else if (i % 2 == 0) sum[i] = sum[i-1] - a[i];
}
for (int i=n;i>=1;i--) {
if (i % 2 == 0) {
if (a[i] >= k) {
ins(0, k-1, i);
} else {
int l = sum[i] % k;
int r = sum[i-1] % k;
if (l < r) ins(l, r, i);
else {
ins(0, r, i);
ins(l, k-1, i);
}
}
} else if (i % 2 == 1) {
int pos = qry(sum[i-1] % k);
lift[i][0].first = pos + 1;
lift[i][0].second = (sum[pos-1] - sum[i-1]) / k;
}
}
for (int i=1;i<lg;i++) {
for (int j=1;j<=n;j++) if (j % 2 == 1) {
lift[j][i].first = lift[lift[j][i-1].first][i-1].first;
lift[j][i].second = lift[j][i-1].second + lift[lift[j][i-1].first][i-1].second;
}
}
while (q--) {
int l, r;
cin >> l >> r;
if (l % 2 == 0) l++;
if (r % 2 == 0) r--;
if (l > r) {
cout << "0\n"; continue;
}
int ans = 0;
for (int i=lg-1;i>=0;i--) {
if (lift[l][i].first && lift[l][i].first <= r+2) {
ans += lift[l][i].second;
l = lift[l][i].first;
}
}
if (l <= r) ans += (sum[r] - sum[l-1]) / k;
cout << ans << "\n";
}
}
