#include <bits/stdc++.h>
using namespace std;
inline int read() {
  register int data = 0, w = 1;
  char ch = 0;
  while (ch != '-' && (ch < '0' || ch > '9')) ch = getchar();
  if (ch == '-') w = -1, ch = getchar();
  while (ch >= '0' && ch <= '9')
    data = (data << 1) + (data << 3) + (ch ^ 48), ch = getchar();
  return data * w;
}
int n, m, a[2200005];
long long sum[2200005], P;
vector<long long> v[2200005];
void pushup(int x) {
  sum[x] = sum[x << 1] + sum[x << 1 | 1];
  vector<long long> &A = v[x << 1], &B = v[x << 1 | 1], &C = v[x];
  int n = A.size() - 1, m = B.size() - 1;
  for (int i = 0, j = 0; i <= n; i++) {
    C[i + j] = min(C[i + j], max(A[i], B[j] + P * i - sum[x << 1]));
    while (j < m && (i == n || v[x << 1][i + 1] - 1 + sum[x << 1] - P * i >=
                                   v[x << 1 | 1][j + 1])) {
      ++j;
      C[i + j] = min(C[i + j], max(A[i], B[j] + P * i - sum[x << 1]));
    }
  }
}
void build(int x, int l, int r) {
  for (int i = 0; i <= r - l + 1; i++) v[x].push_back(1e18);
  if (l == r) {
    v[x][0] = -1e18, v[x][1] = P - a[l];
    sum[x] = a[l];
    return;
  }
  int mid = l + r >> 1;
  build(x << 1, l, mid);
  build(x << 1 | 1, mid + 1, r);
  pushup(x);
}
long long val;
void Clac(int x) {
  int pos = upper_bound(v[x].begin(), v[x].end(), val) - v[x].begin() - 1;
  val += sum[x] - P * pos;
}
void Query(int x, int l, int r, int ql, int qr) {
  if (ql <= l && r <= qr) return Clac(x), void();
  int mid = l + r >> 1;
  if (ql <= mid) Query(x << 1, l, mid, ql, qr);
  if (mid < qr) Query(x << 1 | 1, mid + 1, r, ql, qr);
}
int main() {
  n = read(), m = read(), P = read();
  for (int i = 1; i <= n; i++) a[i] = read();
  build(1, 1, n);
  for (int i = 1; i <= m; i++) {
    int l = read(), r = read();
    val = 0;
    Query(1, 1, n, l, r);
    cout << val << '\n';
  }
  return 0;
}
