#include <bits/stdc++.h>
using namespace std;
const int N = 1e6 + 10;
const long long Inf = 1e16;
int gi() {
  int x = 0, o = 1;
  char ch = getchar();
  while ((ch < '0' || ch > '9') && ch != '-') ch = getchar();
  if (ch == '-') o = -1, ch = getchar();
  while (ch >= '0' && ch <= '9') x = x * 10 + ch - '0', ch = getchar();
  return x * o;
}
int n, m, p, a[N];
vector<long long> f[N << 2];
long long sum[N];
vector<long long> merge(vector<long long> a, vector<long long> b, int l,
                        int r) {
  int mid = (l + r) >> 1;
  long long sl = sum[mid] - sum[l - 1];
  vector<long long> c(int(a.size()) + int(b.size()) - 1, Inf);
  for (int i = 0, j = 0; i < int(a.size()); i++) {
    long long xl = a[i], xr = (i + 1 == int(a.size()) ? Inf : a[i + 1] - 1),
              yl = xl + sl - 1ll * i * p, yr = xr + sl - 1ll * i * p;
    while (j && b[j] > yl) --j;
    while (j < int(b.size()) && (j == 0 || b[j] <= yl)) ++j;
    --j;
    while (j < int(b.size()) && b[j] <= yr)
      c[i + j] = min(c[i + j], max(xl, b[j] + 1ll * i * p - sl)), ++j;
  }
  c[0] = -Inf;
  return c;
}
void build(int x, int l, int r) {
  if (l == r) {
    f[x].push_back(-Inf);
    f[x].push_back(p - a[l]);
    return;
  }
  int mid = (l + r) >> 1;
  build((x << 1), l, mid), build((x << 1 | 1), mid + 1, r);
  f[x] = merge(f[(x << 1)], f[(x << 1 | 1)], l, r);
}
long long qry(int x, int l, int r, int L, int R, long long v) {
  if (L <= l && r <= R)
    return v + sum[r] - sum[l - 1] -
           1ll * p *
               (upper_bound(f[x].begin(), f[x].end(), v) - f[x].begin() - 1);
  int mid = (l + r) >> 1;
  if (R <= mid)
    return qry((x << 1), l, mid, L, R, v);
  else if (L > mid)
    return qry((x << 1 | 1), mid + 1, r, L, R, v);
  else
    return qry((x << 1 | 1), mid + 1, r, L, R, qry((x << 1), l, mid, L, R, v));
}
int main() {
  n = gi(), m = gi(), p = gi();
  for (int i = 1; i <= n; i++) sum[i] = sum[i - 1] + (a[i] = gi());
  build(1, 1, n);
  while (m--) {
    int l = gi(), r = gi();
    cout << qry(1, 1, n, l, r, 0) << '\n';
  }
  return 0;
}
