Numbers codekata

Input Description:
You are given an integer ‘n’ denoting the number of elements in array. Next line contains n space separated integers

Output Description:
Print the max length of that array with sum 0 and print -1 if not possible

Sample Input : 6 -4 3 1 0 0 6

Sample Output : 5

#My code
n=int(input())
n1=input().split()
sum=0
pos=0
for i in range(0,len(n1)):
    sum=sum+int(n1[i])
    if sum==0:
        pos=i+1
        continue
if pos>0:
    print(pos)
else:
    print(-1)
        

Is this test case wrong? or my code is wrong??

Input:

5
1 3 1 0 0 6

Expected Output:

2

Actual Output:

-1