// Problem: B. Replace and Keep Sorted
// Contest: Codeforces - Codeforces Round #701 (Div. 2)
// URL: https://codeforces.com/contest/1485/problem/B
// Memory Limit: 256 MB
// Time Limit: 2000 ms
//
// Powered by CP Editor (https://cpeditor.org)

#include <algorithm>
#include <bitset>
#include <cassert>
#include <chrono>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#define ll long long
#define mod 1000000007

// templates
#define all(v) v.begin(), v.end()
#define F first
#define S second
#define sz(x) (int)x.size()
#define po(x, y) fixed << setprecision(y) << x
#define ss(s) scanf(" %[^\n]%*c", s)
#define sc(n) scanf("%d", &n)
#define sl(n) scanf("%lld", &n)
#define ps(s) printf("%s\n", s)
#define pr(n) printf("%d\n", n)
#define pl(n) printf("%lld\n", n)
#define prs(n) printf("%d ", n)
#define pls(n) printf("%lld ", n)
using namespace std;

const ll inf = (ll)1e15 + 10;
const int N = (int)1e6 + 10;

void solve() {
  int n, q;
  ll k;
  sc(n), sc(q), sl(k);
  vector<ll> a(n + 2, 0);
  for (int i = 1; i <= n; i++) {
    sl(a[i]);
  }
  a[n + 1] = k;
  vector<ll> pre(n + 2, 0);
  for (int i = 1; i <= n; i++) {
    pre[i] += a[i] - a[i - 1] - 1;
    pre[i] += a[i + 1] - a[i] - 1;
    pre[i] += pre[i - 1];
  }
  while (q--) {
    int l, r;
    sc(l), sc(r);
    if (l == r) {
      pl(k - 1);
      continue;
    }
    if (r - l == 1) {
      ll ans = a[l] - 1 + 2 * (a[r] - a[l] - 1) + k - a[r];
      pl(ans);
      continue;
    }
    ll ans = pre[r - 1] - pre[l];
    ans += a[l] - 1 + (a[l + 1] - a[l] - 1);
    ans += a[r] - a[r - 1] - 1;
    ans += k - a[r];
    pl(ans);
  }
}

int main() {
  // #ifndef ONLINE_JUDGE
  // 	freopen("input.txt", "r", stdin);
  // 	freopen("output.txt", "w", stdout);
  // #endif
  int t = 1;
  // sc(t);
  while (t--) {
    solve();
  }
  //	cerr << (float)clock() / CLOCKS_PER_SEC * 1000 << " ms" << endl;
  return 0;
}