#include <bits/stdc++.h>

using namespace std;

ifstream fin("sum2.in");
ofstream fout("sum2.out");
long long n, u, l, i, m = -999999;
long long a, s[500002];
long long q[500002], st = 1, dr;

int main() {
    fin >> n >> l >> u;
    for(i = 1; i <= n; i++) {
        fin >> a;
        s[i] = s[i - 1] + a;
    }
    for(i = 1; i < l; i++) {
        while(dr >= st && s[i] <= s[q[dr]]) dr--;
        q[++dr] = i;
    }
    for(i = l; i <= n; i++) {
        if(i - q[st] > u) st++;
        while(dr >= st && s[i] <= s[q[dr]]) dr--;
        q[++dr] = i;
        m = max(m, s[i] - s[q[st]]);
    }
    fout << m;

    return 0;
}