def main():
    inp = input()
    num = []
    
    count = 0
    ans = 1
    length = len(inp)
    check = 0
    for i in inp:
        wid = ans
         
        while length - count >= wid:
            
            if wid % 2 == 0:
                if inp[count : count + wid // 2] == inp[count + wid -1 : count + wid //2 - 1 : -1]:
                    ans = wid
                    wid += 1
                    check += 1
                else:
                    wid += 1
            else:
                if inp[count : count + wid // 2 ] == inp[count + wid - 1 : count + wid // 2 : -1]:
                    ans = wid
                    wid += 1
                    check += 1
                else:
                    wid += 1
                    
        count += 1
    
    if check >= 2:
        ans = 1

    print(ans)
    
    
if __name__ == '__main__':
    main()