mod = 998244353


def main():
    import sys
    input = sys.stdin.readline

    N = int(input())
    ok = 0
    for _ in range(N):
        v, w = map(int, input().split())
        if w == 1:
            ok = 1
    if ok:
        print("Yes")
    else:
        print("No")


if __name__ == '__main__':
    main()