#include <bits/stdc++.h>
using namespace std;

#define all(v) (v).begin(),(v).end()
#define pb emplace_back
#define rep(i, n) for(int i=0;i<(n);i++)
#define foa(e, v) for(auto& e : v)
#define dout(a) cout<<fixed<<setprecision(10)<<a<<'\n';
#define Cout(a) cout<<a<<'\n';

using ll = long long;
using ld = long double;
using Int = __int128;
template <class T> using pqr = priority_queue<T, vector<T>, greater<T>>;

template <typename T1, typename T2> inline bool chmax(T1 &a, T2 b) {
    bool compare = a < b;
    if(compare) a = b;
    return compare;
}
template <typename T1, typename T2> inline bool chmin(T1 &a, T2 b) {
    bool compare = a > b;
    if(compare) a = b;
    return compare;
}
template <typename T> inline T back(std::set<T> &s) {
    return *s.rbegin();
}
template <typename T> inline T back(std::multiset<T> &s) {
    return *s.rbegin();
}
template <typename T> inline T pop_back(std::set<T> &s) {
    auto it = prev(s.end());
    T val = *it;
    s.erase(it); 
    return val;
}
template <typename T> inline T pop_back(std::multiset<T> &s) {
    auto it = prev(s.end());
    T val = *it;
    s.erase(it); 
    return val;
}

const int dy[8] = {-1, 0, 0, 1, 1, -1, 1, -1};
const int dx[8] = {0, -1, 1, 0, -1, -1, 1, 1};

const ll MOD7 = 1000000007, MOD998 = 998244353, INF = (3LL << 59);
const int inf = 1 << 30;
const char br = '\n';

template<class S, S (*op)(S, S), S (*e)()> struct segtree {
    public:
    explicit segtree(int n) : segtree(vector<S>(n, e())) {}
    explicit segtree(const vector<S>& v) : _n(int(v.size())) {
        size = 1;
        while(size < _n) size *= 2;
        log = __builtin_ctz(size);
        d = vector<S>(2 * size, e());
        for(int i = 0; i < _n; i++) d[size + i] = v[i];
        for(int i = size - 1; i >= 1; i--) { update(i); }
    }

    void set(int p, S x) {
        p += size;
        d[p] = x;
        for(int i = 1; i <= log; i++) update(p >> i);
    }

    S get(int p) const { return d[p + size]; }

    S prod(int l, int r) const {
        S sml = e(), smr = e();
        l += size;
        r += size;

        while(l < r) {
            if(l & 1) sml = op(sml, d[l++]);
            if(r & 1) smr = op(d[--r], smr);
            l >>= 1;
            r >>= 1;
        }
        return op(sml, smr);
    }

   S all_prod() const { return d[1]; }

    template<class F> int max_right(int l, F f) {
        if(l == _n) return _n;
        l += size;
        S sm = e();
        do {
            while(l % 2 == 0) l >>= 1;
            if(!f(op(sm, d[l]))) {
                while(l < size) {
                    l = (2 * l);
                    if(f(op(sm, d[l]))) {
                        sm = op(sm, d[l]);
                        l++;
                    }
                }
                return l - size;
            }
            sm = op(sm, d[l]);
            l++;
        } while((l & -l) != l);
        return _n;
    }

    template<class F> int min_left(int r, F f) {
        if(r == 0) return 0;
        r += size;
        S sm = e();
        do {
            r--;
            while(r > 1 && (r % 2)) r >>= 1;
            if(!f(op(d[r], sm))) {
                while(r < size) {
                    r = (2 * r + 1);
                    if(f(op(d[r], sm))) {
                        sm = op(d[r], sm);
                        r--;
                    }
                }
                return r + 1 - size;
            }
            sm = op(d[r], sm);
        } while((r & -r) != r);
        return 0;
    }  

    private:
    int _n, size, log;
    vector<S> d;

    void update(int k) { d[k] = op(d[2 * k], d[2 * k + 1]); }
};

ll op(ll a, ll b) {
    return max(a, b);
}
ll e() {
    return -INF;
}

void solve() {
    ll n, b, c; cin >> n >> b >> c;
    vector<ll> a(n + 2, 0);
    rep(i, n) cin >> a[i];
    n += 2;
    vector<ll> sum(n + 1, 0);
    rep(i, n) sum[i + 1] = sum[i] + a[i];
    vector<ll> dp(n + 1, -INF);
    dp[0] = 0;
    segtree<ll, op, e> seg(dp);
    ll ans = -INF;
    for(int i = 1; i <= n; i ++) {
        ll num = seg.prod(max(0LL, i - c), i) + sum[i - 1];
        chmax(ans, num);
        seg.set(i, num - sum[i]);
    }
    cout << ans << endl;
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    int testcase = 1; 
    // cin >> testcase;
    while(testcase --) solve();

    return 0;
}