package contest200717;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;

public class E2 {
	InputStream is;
	PrintWriter out;
	String INPUT = "";
	
	void solve()
	{
		int n = ni(), K = ni(), m= ni();
		int[] a = na(n);
		long[] dp = new long[n+1];
		long I = Long.MIN_VALUE / 2;
		Arrays.fill(dp, I);
		dp[0] = 0;
		long[] cum = new long[n+1];
		for(int i = 0;i < n;i++){
			cum[i+1] = cum[i] + a[i];
		}
		
		for(int i = 0;i < K;i++){
			long[] ndp = new long[n+1];
			Arrays.fill(ndp, I);
			
			long[][] es = new long[n+1][];
			for(int k = 0;k <= n;k++){
				es[k] = new long[]{cum[k], k};
			}
			{
				Arrays.sort(es, (x, y) -> {
					if(x[0] != y[0])return Long.compare(x[0], y[0]);
					return Long.compare(x[1], y[1]);
				});
	
				SegmentTreeRMQL st = new SegmentTreeRMQL(n+1);
				for(long[] e : es){
					int ind = (int)e[1];
					ndp[ind] = Math.max(ndp[ind], -st.minx(Math.max(ind-m, 0), ind) + cum[ind]);
					st.update(ind, -(dp[ind]-e[0]));
				}
			}
			
			{
				Arrays.sort(es, (x, y) -> {
					if(x[0] != y[0])return -Long.compare(x[0], y[0]);
					return Long.compare(x[1], y[1]);
				});
	
				SegmentTreeRMQL st = new SegmentTreeRMQL(n+1);
				for(long[] e : es){
					int ind = (int)e[1];
					ndp[ind] = Math.max(ndp[ind], -st.minx(Math.max(ind-m, 0), ind) - cum[ind]);
					st.update(ind, -(dp[ind]+e[0]));
				}
			}
			
//			for(int j = 0;j <= n;j++){
//				long max = I;
//				for(int k = Math.max(0, j-m);k < j;k++){
//					max = Math.max(max, Math.abs(cum[j] - cum[k]) + dp[k]);
//				}
//				ndp[j] = max;
//			}
			
			dp = ndp;
		}
		out.println(dp[n]);
	}
	
	public static class SegmentTreeRMQL {
		public int M, H, N;
		public long[] st;
		
		public SegmentTreeRMQL(int n)
		{
			N = n;
			M = Integer.highestOneBit(Math.max(N-1, 1))<<2;
			H = M>>>1;
			st = new long[M];
			Arrays.fill(st, 0, M, Long.MAX_VALUE);
		}
		
		public SegmentTreeRMQL(long[] a)
		{
			N = a.length;
			M = Integer.highestOneBit(Math.max(N-1, 1))<<2;
			H = M>>>1;
			st = new long[M];
			for(int i = 0;i < N;i++){
				st[H+i] = a[i];
			}
			Arrays.fill(st, H+N, M, Long.MAX_VALUE);
			for(int i = H-1;i >= 1;i--)propagate(i);
		}
		
		public void update(int pos, long x)
		{
			st[H+pos] = x;
			for(int i = (H+pos)>>>1;i >= 1;i >>>= 1)propagate(i);
		}
		
		private void propagate(int i)
		{
			st[i] = Math.min(st[2*i], st[2*i+1]);
		}
		
		public long minx(int l, int r){
			long min = Long.MAX_VALUE/2;
			if(l >= r)return min;
			while(l != 0){
				int f = l&-l;
				if(l+f > r)break;
				long v = st[(H+l)/f];
				if(v < min)min = v;
				l += f;
			}
			
			while(l < r){
				int f = r&-r;
				long v = st[(H+r)/f-1];
				if(v < min)min = v;
				r -= f;
			}
			return min;
		}
		
		public long min(int l, int r){ return l >= r ? 0 : min(l, r, 0, H, 1);}
		
		private long min(int l, int r, int cl, int cr, int cur)
		{
			if(l <= cl && cr <= r){
				return st[cur];
			}else{
				int mid = cl+cr>>>1;
				long ret = Long.MAX_VALUE;
				if(cl < r && l < mid){
					ret = Math.min(ret, min(l, r, cl, mid, 2*cur));
				}
				if(mid < r && l < cr){
					ret = Math.min(ret, min(l, r, mid, cr, 2*cur+1));
				}
				return ret;
			}
		}
		
		public int firstle(int l, long v) {
			if(l >= H)return -1;
			int cur = H+l;
			while(true){
				if(st[cur] <= v){
					if(cur >= H)return cur-H;
					cur = 2*cur;
				}else{
					cur++;
					if((cur&cur-1) == 0)return -1;
					if((cur&1)==0)cur>>>=1;
				}
			}
		}
		
		public int lastle(int l, long v) {
			if(l < 0)return -1;
			int cur = H+l;
			while(true){
				if(st[cur] <= v){
					if(cur >= H)return cur-H;
					cur = 2*cur+1;
				}else{
					if((cur&cur-1) == 0)return -1;
					cur--;
					if((cur&1)==1)cur>>>=1;
				}
			}
		}
	}

	
	void run() throws Exception
	{
		is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
		out = new PrintWriter(System.out);
		
		long s = System.currentTimeMillis();
		solve();
		out.flush();
		if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
//		Thread t = new Thread(null, null, "~", Runtime.getRuntime().maxMemory()){
//			@Override
//			public void run() {
//				long s = System.currentTimeMillis();
//				solve();
//				out.flush();
//				if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
//			}
//		};
//		t.start();
//		t.join();
	}
	
	public static void main(String[] args) throws Exception { new E2().run(); }
	
	private byte[] inbuf = new byte[1024];
	public int lenbuf = 0, ptrbuf = 0;
	
	private int readByte()
	{
		if(lenbuf == -1)throw new InputMismatchException();
		if(ptrbuf >= lenbuf){
			ptrbuf = 0;
			try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
			if(lenbuf <= 0)return -1;
		}
		return inbuf[ptrbuf++];
	}
	
	private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
	private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
	
	private double nd() { return Double.parseDouble(ns()); }
	private char nc() { return (char)skip(); }
	
	private String ns()
	{
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	
	private char[] ns(int n)
	{
		char[] buf = new char[n];
		int b = skip(), p = 0;
		while(p < n && !(isSpaceChar(b))){
			buf[p++] = (char)b;
			b = readByte();
		}
		return n == p ? buf : Arrays.copyOf(buf, p);
	}
	
	private int[] na(int n)
	{
		int[] a = new int[n];
		for(int i = 0;i < n;i++)a[i] = ni();
		return a;
	}
	
	private long[] nal(int n)
	{
		long[] a = new long[n];
		for(int i = 0;i < n;i++)a[i] = nl();
		return a;
	}
	
	private char[][] nm(int n, int m) {
		char[][] map = new char[n][];
		for(int i = 0;i < n;i++)map[i] = ns(m);
		return map;
	}
	
	private int[][] nmi(int n, int m) {
		int[][] map = new int[n][];
		for(int i = 0;i < n;i++)map[i] = na(m);
		return map;
	}
	
	private int ni() { return (int)nl(); }
	
	private long nl()
	{
		long num = 0;
		int b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); }
}