from heapq import heapify, heappop, heappush
from collections import defaultdict 


def main():
    N = int(input())
    deg = [0]*N
    dic = defaultdict(list)
    for i in range(N):
        a,b = map(int,input().split())
        a -= 1; b -= 1
        deg[a] += 1
        deg[b] += 1
        dic[a].append((b,i)) #行先、辺の番号
        dic[b].append((a,i))
        
    PQ = []
    #for i in range(N):
    #    heappush(PQ,(deg[i],i))
    ret = []
    used_point = set([])
    used_edge = set([])
    for i in range(N):
        if i in used_point: continue
        heappush(PQ,(deg[i],i))
        while PQ:
            #print(PQ)
            d,v = heappop(PQ)
            #print(d,v)
            for u,edge_idx in dic[v]:
                if v in used_point and u in used_point: continue
                if edge_idx in used_edge: continue
                if v in used_point:
                    ret.append(u)
                    used_point.add(u)
                    used_edge.add(edge_idx)
                    deg[v] -= 1
                    deg[u] -= 1
                elif u in used_point:
                    ret.append(v)
                    used_point.add(v)
                    used_edge.add(edge_idx)
                    deg[v] -= 1
                    deg[u] -= 1
                else:
                    ret.append(v)
                    deg[v] -= 1
                    deg[u] -= 1
                    used_point.add(v)
                    used_edge.add(edge_idx)
                    #print("push",u,edge_idx)
                    heappush(PQ,(deg[u],u))
    if len(ret) == N:
        print('Yes')
        ret = [x+1 for x in ret]
        print(*ret,sep="\n")
    else:
        print('No')

if __name__ == '__main__':
    main()