#include <bits/stdc++.h>
using namespace std;
const int mx=3e5+5;
int n,k,q,a,b;
int t[mx];
long long pref[mx],dp[mx];
void solve(int a,int b){
    for(int i=a-1;i<=b;++i){
        dp[i]=0;
    }
    for(int i=a+k-1;i<=b;++i){
        dp[i]=max(dp[i],dp[i-1]);
        dp[i]=max(dp[i],pref[i]-pref[i-k]+dp[i-k]);
    }
    cout<<dp[b]<<"\n";
}
int main(){
    ios::sync_with_stdio(false);
    cin>>n>>k>>q;
    for(int i=1;i<=n;++i){
        cin>>t[i];
        pref[i]=pref[i-1]+t[i];
    }
    for(int i=0;i<q;++i){
        cin>>a>>b;
        solve(a,b);
    }
    return 0;
}