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

    S = input().rstrip('\n')
    N = len(S)

    seen = set()
    new = [s for s in S]
    for i in range(0, N, 2):
        seen.add(S[i])
        new[i] = ' '
    for i in range(1, N, 2):
        if S[i] in seen:
            new[i] = ' '
    exist = []
    for i in range(N):
        if new[i] != ' ':
            exist.append(i)
    if len(exist) >= 2:
        diff = [exist[i+1] - exist[i] for i in range(len(exist) - 1)]
        if min(diff) == max(diff) == 2:
            print('Yes')
            exit()

    seen = set()
    new = [s for s in S]
    for i in range(1, N, 2):
        seen.add(S[i])
        new[i] = ' '
    for i in range(0, N, 2):
        if S[i] in seen:
            new[i] = ' '
    exist = []
    for i in range(N):
        if new[i] != ' ':
            exist.append(i)
    if len(exist) >= 2:
        diff = [exist[i + 1] - exist[i] for i in range(len(exist) - 1)]
        if min(diff) == max(diff) == 2:
            print('Yes')
            exit()

    print('NO')


if __name__ == '__main__':
    main()