import sys
sys.setrecursionlimit(1 << 25)

def main():
    import sys
    input = sys.stdin.read
    data = input().split()
    idx = 0
    N = int(data[idx])
    idx += 1
    
    A = []
    B = []
    for _ in range(N):
        a = int(data[idx])
        b = int(data[idx+1])
        A.append(a)
        B.append(b)
        idx += 2
    
    # Check if all balls are present
    present = [False] * (N + 1)
    for a, b in zip(A, B):
        present[a] = True
        present[b] = True
    for v in range(1, N + 1):
        if not present[v]:
            print("No")
            return
    
    # Union-Find structure to manage connected components
    parent = list(range(N + 1))
    size = [1] * (N + 1)
    edge_count = [0] * (N + 1)
    
    def find(u):
        while parent[u] != u:
            parent[u] = parent[parent[u]]
            u = parent[u]
        return u
    
    for a, b in zip(A, B):
        root_a = find(a)
        root_b = find(b)
        if root_a == root_b:
            edge_count[root_a] += 1
        else:
            if size[root_a] < size[root_b]:
                root_a, root_b = root_b, root_a
            parent[root_b] = root_a
            size[root_a] += size[root_b]
            edge_count[root_a] += edge_count[root_b] + 1
    
    # Check if each component's size equals edge count
    roots = set()
    for v in range(1, N + 1):
        roots.add(find(v))
    valid = True
    for root in roots:
        if size[root] != edge_count[root]:
            valid = False
            break
    if not valid:
        print("No")
        return
    
    # Greedy selection
    selected = [False] * (N + 1)
    ans = []
    for i in range(N):
        a = A[i]
        b = B[i]
        if not selected[a]:
            selected[a] = True
            ans.append(a)
        elif not selected[b]:
            selected[b] = True
            ans.append(b)
        else:
            print("No")
            return
    
    print("Yes")
    for num in ans:
        print(num)

if __name__ == "__main__":
    main()