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

using i8 = int8_t;
using i16 = int16_t;
using i32 = int32_t;
using i64 = int64_t;
using isize = ptrdiff_t;
using u8 = uint8_t;
using u16 = uint16_t;
using u32 = uint32_t;
using u64 = uint64_t;
using usize = size_t;
using f32 = float_t;
using f64 = double_t;

inline constexpr i32 Modulus = 1e9 + 7;

template <typename TScalar, typename... TRest>
inline constexpr TScalar Max(TScalar first, TRest... rest)
{
    static_assert((is_same_v<TScalar, TRest> && ...), "All arguments must have the same type");
    if constexpr (sizeof...(rest) == 0)
        return first;
    else
        return (first > Max(rest...)) ? first : Max(rest...);
}

int main(void)
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    usize n, a, b;
    cin >> n >> a >> b;

    vector<i64> prefixSums(n + 1);
    for (usize index = 1; index <= n; index += 1)
    {
        i32 value;
        cin >> value;
        prefixSums[index] = prefixSums[index - 1] + value;
    }

    i64 maximumSum = numeric_limits<i64>::min();
    multiset<i64, less<i64>> subtractable;

    for (usize index = a; index <= n; index += 1)
    {
        if (index > b)
        {
            subtractable.erase(subtractable.find(prefixSums[index - b - 1]));
        }

        subtractable.insert(prefixSums[index - a]);
        maximumSum = Max(maximumSum, prefixSums[index] - *subtractable.begin());
    }

    cout << maximumSum;

    return 0;
}