import sys
input=sys.stdin.readline
a=int(input())
import math
for i in range(a):
    n,k,x=map(int,input().split())
    z=list(map(int,input().split()))
    dp=[[[0 for i in range(2)] for i in range(k+1)] for i in range(n)]


    # dp[i][j][0] denotest ith index tak j use karlei
    #and the current maximum is how much

    # dp[i][j][1] denotes ith index tak j use karlie and overall maximum is how much
    maxa=0
    for i in range(len(z)):

        for j in range(k+1):
            if(i+1<j):
                dp[i][j][0]=-math.inf
                dp[i][j][1]=-math.inf
                continue
            if(i==0 and j==0):
                dp[i][j][0]=max(0,z[i]-x)
                dp[i][j][1]=dp[i][j][0]
            elif(i==0 and j==1):
                dp[i][j][0]=max(z[i]+x,0)
                dp[i][j][1]=dp[i][j][0]
            elif(j==0):
                dp[i][j][0]=max(dp[i-1][j][0]+z[i]-x,0)
                dp[i][j][1]=max(dp[i-1][j][1],dp[i][j][0])
            else:
                dp[i][j][0]=max(dp[i-1][j-1][0]+z[i]+x,dp[i-1][j][0]+z[i]-x,0)
                dp[i][j][1]=max(dp[i][j][0],dp[i-1][j][1],dp[i-1][j-1][1])

            if(j==k):
                maxa=max(maxa,dp[i][j][1])
    print(maxa)