N = int(input())
A = [list(map(int, input().split())) for i in range(N)]

a = 0
for i in range(N-1):
    if a == 1:
        break
    for j in range(i+1, N):
        if A[i] == A[j]:
            print("Yes")
            a = 1
            break

if a == 0:
  print("No")