import std.conv, std.functional, std.range, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, std.numeric, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }


enum INF = 10L^^18;

void main() {
  try {
    for (; ; ) {
      const N = readInt();
      const K = readInt();
      const M = readInt();
      auto A = new long[N];
      foreach (i; 0 .. N) {
        A[i] = readLong();
      }
      
      auto ASum = new long[N + 1];
      foreach (i; 0 .. N) {
        ASum[i + 1] = ASum[i] + A[i];
      }
      
      auto ps = new Tuple!(long, int)[N + 1];
      foreach (i; 0 .. N + 1) {
        ps[i] = tuple(ASum[i], i);
      }
      ps.sort;
      auto qs = new int[N + 1];
      foreach (j; 0 .. N + 1) {
        qs[ps[j][1]] = j;
      }
      
      auto crt = new long[N + 1];
      crt[] = -INF;
      crt[0] = 0;
      foreach (k; 0 .. K) {
        auto nxt = new long[N + 1];
        nxt[] = -INF;
        alias Entry = Tuple!(long, "score", int, "j");
        DList!Entry que0, que1;
        foreach (i; k + 1 .. N + 1) {
          {
            const e = Entry(crt[i - 1] - ASum[i - 1], i - 1);
            for (; !que0.empty && que0.back.score <= e.score; que0.removeBack) {}
            que0.insertBack(e);
          }
          {
            const e = Entry(crt[i - 1] + ASum[i - 1], i - 1);
            for (; !que1.empty && que1.back.score <= e.score; que1.removeBack) {}
            que1.insertBack(e);
          }
          for (; !que0.empty && que0.front.j < i - M; que0.removeFront) {}
          for (; !que1.empty && que1.front.j < i - M; que1.removeFront) {}
          if (!que0.empty) chmax(nxt[i], que0.front.score + ASum[i]);
          if (!que1.empty) chmax(nxt[i], que1.front.score - ASum[i]);
        }
        debug {
          writeln(k + 1, ": ", nxt);
        }
        crt = nxt;
      }
      writeln(crt[N]);
    }
  } catch (EOFException e) {
  }
}