Help me in solving ASTHIT problem

help
,
1

My issue

i am finding a zero and then im doing it…1
5
1 11
1 2
1 3
1 2
0 4
for this my program is giving correct output 0 but expcetd output is something really wierd

My code

# cook your dish here
t=int(input())

for i in range(t):
    n=int(input())
    
    a=[]
    b=[]
    c=[]

    for j in range(n):
        x,y=map(int,input().split())
        c.insert(j,j+1)
        a.insert(j,x)
        b.insert(j,y)

    for j in range(n):
        if a[j]==0:
            k=j-1
            while k>=0:
                if a[k]==1:
                    if b[k]==b[j]:
                        a[k]=-1
                        a[j]=-1
                    elif b[k]>b[j]:
                        b[k]+=b[j]
                        a[j]=-1
                    else:
                        b[j]+=b[k]
                        a[k]=-1
                k=k-1
    flag=0
    for j in range(n):
        if a[j]!=-1:
            flag+=1
    print(flag)
    for j in range(n):
        if a[j]!=-1:
            print(c[j])

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Problem Link: Practice Problem in - CodeChef