import sys

def main():
    sys.setrecursionlimit(1 << 25)
    N = int(sys.stdin.readline())
    pairs = []
    for _ in range(N):
        a, b = map(int, sys.stdin.readline().split())
        pairs.append((a, b))
    
    last = [0] * (N + 1)  # 1-based
    present = [False] * (N + 1)
    for i in range(N):
        a, b = pairs[i]
        present[a] = True
        present[b] = True
        if i + 1 > last[a]:
            last[a] = i + 1
        if i + 1 > last[b]:
            last[b] = i + 1
    
    # Check if all balls are present
    for x in range(1, N + 1):
        if not present[x]:
            print("No")
            return
    
    used = [False] * (N + 1)
    ans = []
    for i in range(N):
        a, b = pairs[i]
        current_step = i + 1  # 1-based
        a_last = (last[a] == current_step)
        b_last = (last[b] == current_step)
        
        if a_last and b_last:
            if not used[a] and not used[b]:
                print("No")
                return
            if not used[a]:
                ans.append(a)
                used[a] = True
            else:
                ans.append(b)
                used[b] = True
        elif a_last:
            if not used[a]:
                ans.append(a)
                used[a] = True
            else:
                ans.append(b)
                if not used[b]:
                    used[b] = True
        elif b_last:
            if not used[b]:
                ans.append(b)
                used[b] = True
            else:
                ans.append(a)
                if not used[a]:
                    used[a] = True
        else:
            # Choose the one that is not used, if possible
            if not used[a]:
                ans.append(a)
                used[a] = True
            elif not used[b]:
                ans.append(b)
                used[b] = True
            else:
                ans.append(a)  # arbitrary choice
    
    # Final check
    for x in range(1, N + 1):
        if not used[x]:
            print("No")
            return
    
    print("Yes")
    for choice in ans:
        print(choice)

if __name__ == "__main__":
    main()