#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
#define rep(i, l, r) for (ll i = (l); i < (r); ++i)
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pl = pair<ll,ll>;
using vi = vector<int>;
using vl = vector<ll>;
using vvl = vector<vector<ll>>;
using vvvl = vector<vector<vector<ll>>>;
template<class T> using pq_ = priority_queue<T, vector<T>, greater<T>>;
#define sz(x) (int)(x).size()
typedef pair<int, int> pii;
using mint=modint998244353;
// g++ a.cpp -std=c++23 -I.
// g++ -std=c++23 -I. a.cpp -o main
// g++ -std=c++23 -I. anaive.cpp -o naive
// g++ -std=c++23 -I. agene.cpp -o gene

ll op(ll a, ll b) {
    return min(a, b);
}

ll e() {
    return (ll)((ll)1e18);
}

int main(){
    ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    ll n,b,c;
    cin>>n>>c>>b;
    segtree<ll, op, e> seg(n+1);
    vl z(n);
    rep(i,0,n){
        cin>>z[i];
    }
    ll u=0;
    seg.set(0,0);
    rep(i,0,n){
        if(c!=2||i==0)seg.set(i+1,seg.prod(max((ll)0,i+1-b),i+1)+z[i]);
        else seg.set(i+1,seg.prod(max((ll)0,i+1-b),i)+z[i]);
        u+=z[i];
    }
    cout<<u-seg.prod(max((ll)0,n+1-b),n+1)<<endl;
}