with open('24_5810.txt', 'r') as f:
    data = f.read().strip() +'___'
skip = 0
c = 1
k = 0
k_max = 0
for i in range(len(data) - 3):
    if skip:
        if c == skip:
            skip = 0
            c = 1
        else:
            c += 1
            continue
    if data[i] + data[i + 1] + data[i + 2] == 'XYZ':
        skip = 3
        k += 3
        k_max = max(k, k_max)

    elif data[i] + data[i + 1] in ['XY', 'YZ']:
        skip = 2
        k += 2
        k_max = max(k, k_max)
    else:
        k = 0
        skip = 1
        c = 1

print(k_max)