import bisect

n=int(input())
L=[list(map(int,input().split())) for _ in range(n)]
E=[-1]*(n+1)
B=[]
S=set()
for i in range(n):
    a,b=L[i]
    if a==1:
        E[i+1]=i
        S.add(i)
    if b==1:
        B.append(i)
for i in range(n):
    a,b=L[i]
    if b==2:
        id=bisect.bisect_left(B,i+1)
        E[B[id]]=i
        S.add(i)

ans=[]
for i in range(n):
    if i not in S:
        ans.append(i+1)
        S.add(i)
        while E[i]!=-1:
            i=E[i]
            ans.append(i+1)
    else:
        pass
print(*ans,sep="\n")