Help me in solving P4149 problem

help
,
1

My issue

I am not able to find out here at which test case it is failing ?
According to me it is handling all the test cases correctly.

My code

# cook your dish here
# cook your dish here
t=int(input())
for i in range(t):
    n=int(input())
    l=list(map(int,input().split()))
    l.sort()
    c=0
    for i in range(n):
        if l[i]<=0:
            c=c+1
    if c%2!=0:
        c=c-1
    for i in range(c):
        l[i]=abs(l[i])
    d=0
    for i in range(n):
        d+=l[i]
    print(d)

Problem Link: Maximise Sum Practice Coding Problem