#nullable enable

#region
var (_input, _iter) = (Array.Empty<string>(), 0);
T I<T>() where T : IParsable<T>
{
    while (_iter >= _input.Length) (_input, _iter) = (Console.ReadLine()!.Split(' ', StringSplitOptions.RemoveEmptyEntries), 0);
    return T.Parse(_input[_iter++], null);
}
#endregion

var n = I<int>();
var b = Math.Min(I<int>(), 3);
var c = I<int>();
var sz = new long[n + 1];
for (var i = 0; i < n; i++) sz[i + 1] = sz[i] + I<int>();

var dp = new long[n + 1];
dp.AsSpan().Fill(long.MinValue / 8);
dp[c - 2] = sz[c - 2];
dp[c - 1] = sz[c - 1];
for (var i = c - 2; i < n; i++)
{
    var v = dp[i];
    if (v < 0) continue;
    for (var x = c - 2; x < c; x++) for (var y = 1; y < b; y++)
    {
        if (i + y >= n) continue;
        var j = Math.Min(i + x + y, n);
        dp[j] = Math.Max(dp[j], v + sz[j] - sz[j - x]);
    }
}
var ans = dp[n];
Console.WriteLine(ans);