#!/usr/bin/python

with open("6.in") as fh:
    for line in fh:
        line = line.strip()

        start = 0
        end = 14
        for i in range(len(line)):
            window = line[start:end]
            if len(set(window)) == 14:
                print(end)
                break
            else:
                start += 1
                end += 1