#include <bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define fr first
#define sc second
#define mod 998244353
#define len(x) x.size()
#define min3(a, b, c) min(a, min(b, c))
#define max3(a, b, c) max(a, max(b, c))
#define all(v) v.begin(), v.end()
#define alla(a,n) a, a + n
#define fast_io ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll, ll> pll;
typedef vector<ll> vll;
typedef vector<pll> vpll;
typedef vector<vll> vvll;
typedef vector<string> vs;

int32_t main() {

#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif

    fast_io;
    
        
        ll n, q, k; cin>>n>>q>>k;
        ll arr[n];
        for(ll i=0;i<n;i++){
            cin>>arr[i];
        }

        ll ans[n];
        memset(ans, 0, sizeof(ll)*n);
        ans[0]+=arr[0]-1;
        ans[n-1]+=k-arr[n-1];
        for(ll i=0;i<n;i++){

            if(i!=0 && arr[i]!=arr[i-1]){
                ans[i]+=arr[i]-arr[i-1]-1;
            }
            if(i!=n-1 && arr[i]!=arr[i+1]){
                ans[i]+=arr[i+1]-arr[i]-1;
            }
        }

        for(ll i=1;i<n;i++){
            ans[i]+=ans[i-1];
            // cout<<ans[i]<<" ";
        }
        for(ll j=0;j<q;j++){

            ll x, y; cin>>x>>y;
            ll finalAns= ans[y-1];
            if(x>=2){
                finalAns-=ans[x-2];
            }

            if(x!=1){
                finalAns+=arr[x-2];
            }

            if(y!=n){
                finalAns+=k-arr[y]+1;
            }
            cout<<finalAns<<endl;
        }


    
    return 0;

}