#include <bits/stdc++.h>
using namespace std;
template <typename T>
void maxtt(T &t1, T t2) {
  t1 = max(t1, t2);
}
template <typename T>
void mintt(T &t1, T t2) {
  t1 = min(t1, t2);
}
bool debug = 0;
int n, m, k;
int dx[4] = {0, 1, 0, -1}, dy[4] = {1, 0, -1, 0};
string direc = "URDL";
const long long MOD2 = (long long)998244353 * (long long)998244353;
long long ln, lk, lm;
void etp(bool f = 0) {
  puts(f ? "YES" : "NO");
  exit(0);
}
void addmod(int &x, int y, int mod = 998244353) {
  assert(y >= 0);
  x += y;
  if (x >= mod) x -= mod;
  assert(x >= 0 && x < mod);
}
void et(int x = -1) {
  printf("%d\n", x);
  exit(0);
}
long long fastPow(long long x, long long y, int mod = 998244353) {
  long long ans = 1;
  while (y > 0) {
    if (y & 1) ans = (x * ans) % mod;
    x = x * x % mod;
    y >>= 1;
  }
  return ans;
}
long long gcd1(long long x, long long y) { return y ? gcd1(y, x % y) : x; }
int a[1000035], P;
struct nd {
  vector<long long> vp;
  long long len;
  friend nd operator+(const nd &x, const nd &y) {
    nd res;
    res.vp.resize(x.vp.size() + y.vp.size() - 1, (1LL << 60));
    for (int i = 0, j = 0; i < x.vp.size(); i++) {
      long long A = x.vp[i] + x.len - (long long)P * i;
      long long B = (i + 1 == x.vp.size() ? (1LL << 60) : x.vp[i + 1] - 1) +
                    x.len - (long long)P * i;
      while (j > 0 && y.vp[j] > B) j--;
      while (j < y.vp.size() && (j == 0 || y.vp[j] <= A)) j++;
      for (j--; j < y.vp.size() && y.vp[j] <= B; j++) {
        mintt(res.vp[i + j], max(x.vp[i], y.vp[j] - x.len + (long long)P * i));
      }
    }
    res.vp[0] = -(1LL << 60);
    res.len = x.len + y.len;
    return res;
  }
} T[1000035 * 4];
void build(int rt, int l, int r) {
  if (l == r) {
    T[rt].vp.push_back(-(1LL << 60));
    T[rt].len = a[l];
    T[rt].vp.push_back(P - a[l]);
    return;
  }
  int mid = (l + r) / 2;
  build((rt << 1), l, mid);
  build((rt << 1 | 1), mid + 1, r);
  T[rt] = T[(rt << 1)] + T[(rt << 1 | 1)];
}
long long qy(int rt, int l, int r, int L, int R, long long cur) {
  if (L <= l && r <= R) {
    auto it =
        upper_bound(T[rt].vp.begin(), T[rt].vp.end(), cur) - T[rt].vp.begin();
    it--;
    return cur + T[rt].len - (long long)it * P;
  }
  int mid = (l + r) / 2;
  if (R <= mid)
    return qy((rt << 1), l, mid, L, R, cur);
  else if (L > mid)
    return qy((rt << 1 | 1), mid + 1, r, L, R, cur);
  else {
    long long z = qy((rt << 1), l, mid, L, mid, cur);
    return qy((rt << 1 | 1), mid + 1, r, mid + 1, R, z);
  }
}
void fmain(int tid) {
  scanf("%d%d%d", &n, &m, &P);
  for (int(i) = 1; (i) <= (int)(n); (i)++) scanf("%d", a + i);
  build(1, 1, n);
  for (int(i) = 1; (i) <= (int)(m); (i)++) {
    int l, r;
    scanf("%d%d", &l, &r);
    printf("%lld\n", qy(1, 1, n, l, r, 0));
  }
}
int main() {
  int t = 1;
  for (int(i) = 1; (i) <= (int)(t); (i)++) {
    fmain(i);
  }
  return 0;
}
