#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
#define endl '\n'
//#pragma GCC optimize("Ofast")
using namespace std;
using ll = long long;
using ld = long double;
using pii = pair < int, int >;
using pll = pair < ll, ll >;
const ll INF = 2e18;
const ll DIM = 500007;
const ld PI = 3.1415926535;
const int mod = 998244353;
struct jump {
int toX;
ll val;
};
jump j[19][DIM][10];
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
#ifdef IloveCP
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
ll n, q, k;
cin >> n >> q >> k;
vector < ll > a(n + 1);
for(int i = 1; i <= n; i++) cin >> a[i];
for(int i = n; i >= 1; i--) {
if(i % 2 == 0) continue;
for(int x = 0; x < k; x++) {
ll tmp = a[i];
ll bal = x;
if(bal + tmp >= k) {
j[0][i][x].val++;
tmp -= (k - bal);
bal = 0;
}
j[0][i][x].val += tmp / k;
tmp %= k;
if(i + 2 <= n) {
bal = max(bal + tmp - a[i + 1], (ll)0);
j[0][i][x].toX = bal;
}
for(int p = 1; p < 19; p++) {
if(i + (1 << p) <= n) {
j[p][i][x].val = j[p - 1][i][x].val + j[p - 1][i + (1 << p)][j[p - 1][i][x].toX].val;
j[p][i][x].toX = j[p - 1][i + (1 << p)][j[p - 1][i][x].toX].toX;
}
else {
j[p][i][x] = j[p - 1][i][x];
}
}
//cout << j[0][i][x].val << " " << j[0][i][x].toX << endl;
//cout << j[1][i][x].val << " " << j[1][i][x].toX << endl;
}
}
for(int i = 0; i < q; i++) {
int l, r;
cin >> l >> r;
if(l % 2 == 0) l++;
if(r % 2 == 0) r--;
if(l > r) {
cout << 0 << endl;
continue;
}
int curr = l;
ll bal = 0;
ll res = 0;
for(int p = 18; p >= 0; p--) {
if(curr + (1 << (p + 1)) <= r) {
res += j[p][curr][bal].val;
bal = j[p][curr][bal].toX;
curr += (1 << (p + 1));
}
}
res += j[0][curr][bal].val;
cout << res << endl;
}
return 0;
}
