#include <bits/stdc++.h>
using namespace std;
#define int long long
#define IOS ios_base::sync_with_stdio(0);cin.tie(0)
#define infinite 9123456789
#define PRECISION cout.precision(3); cout.setf(ios::fixed);
#define db cout << "Debug" << "\n";
#define ler_entrada freopen("test_input.txt", "r", stdin);

int n, q, k, a[100010];

void solve(){
	cin >> n >> q >> k;
	
	for(int i=1; i<=n; i++) cin >> a[i];
	vector<int> pref(n+10);
	
	pref[1] = a[2] - 2;
	
	for(int i=2; i<n; i++) pref[i] = pref[i-1] + a[i+1]-a[i-1]-2;
	
	pref[n] = k - a[n-1] - 1 + pref[n-1];
	
	for(int i=1; i<=q; i++){
		int l, r; cin >> l >> r;
		
		int quant = r - l + 1, dentro = a[r] - a[l] + 1 - quant;
		
		cout << k - quant + dentro << "\n";
		continue;
		
		if(l == r){
			cout << k-1 << "\n";
			continue;
		}
		if(l+1 == r){
			cout << k-2 << "\n";
			continue;
		}
		
		int resp = 0;
		resp += pref[r-1]-pref[l+1] + k - 1;
		cout << resp << "\n";
	}
}

signed main(){
	IOS;
	solve();
}