ll@N,@K,@A[N],@C[N],B[N][N]={},k,b,c;rep(i,N)B[i][i]=1LL<<C[i];rep(l,1,N)rep(i,N){k=i+l;rep(j,i,k){b=B[i][j%N];c=B[(j+1)%N][k%N];REP(d,K+1)B[i][k%N]|=b&c<<d|b&c>>d|b<<d&c|b>>d&c;}}wt(max[(i,l),0,N@B[i][(i+l)%N]](sum[m,i,i+l+1](A[m%N])));