ll M=1<<17,N,K,A[2d5],a[2d5],b[2d5],c[2d5],z=1d18,m,j;{rd(N,K,A(N));rep(i,N)a[b[i]=i]=A[i];sortA(N,a,b);rep(i,N)c[b[i]]=i;fenwick<ll> f,g;f.malloc(M);f.init(M);g.malloc(M);g.init(M);rep(i,N){f.add(c[i],1);g.add(c[i],A[i]);if(i>=K-1){m=f.kth(K/2);z<?=g.get(M-1)-2*g.get(m)-(K-2*f.get(m))*a[m];f.add(c[j=i-K+1],-1);g.add(c[j],-A[j]);}}wt(z);}