/*input
6 5 10
2 4 6 7 8 9
1 4
1 2
3 5
1 6
5 5
*/

#include <bits/stdc++.h>
#define ll long long

using namespace std;

void run() {
	int n, q, i;
	ll k;
	cin >> n >> q >> k;
	vector<ll> a(n);
	for(auto &x : a)
		cin >> x;
	vector<ll> pref(n + 1, 0);
	for(i=0; i<n; i++) {
		pref[i + 1] = pref[i] + a[i] - (i ? a[i - 1] + 1 : 1) + (i + 1 < n ? (a[i + 1] - a[i] - 1) : 0);
		// cout << pref[i + 1] << " ";
	}
	// cout << endl;
	while(q--) {
		int l, r;
		cin >> l >> r;
		if(l == r) {
			cout << k - 1 << endl;
			continue;
		}
		ll ret = pref[r] - pref[l - 1];
		// cout << "ret: " << ret << endl;
		if(l > 1) {
			ret -= a[l - 1] - a[l - 2] - 1;
			ret += a[l - 1] - 1;
		}
		if(r < n && r > 0) {
			ret -= a[r] - a[r - 1] - 1;
		}
		ret += k - a[r - 1];
		cout << ret << endl;
	}
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout << fixed << setprecision(10);
	run();
}
