first = input()
x = first[0]
num = [0]
ans = []
n = 1
for i in range(1,len(first)):
    if x == first[i]:
        n += 1
    else:
        num.add(n)
        n=1
        x = first[i]

for i in range(len(num)):
    ans.add(min(num[i],num[i+1]))
    
print(max(ans))