#!/usr/bin/env python3
# -*- coding: utf-8 -*-

data = ""

# parse input
input_file = open("input", "r")
for line in input_file:
    line = line.strip()
    data += line
input_file.close()

# data = "mjqjpqmgbljsphdztnvjfqwrcgsmlb"
# data = "bvwbjplbgvbhsrlpgdmjqwftvncz"
# data = "nppdvjthqldpwncqszvftbrmjlhg"
# data = "nznrnfrfntjfmvfwmzdfjlvtqnbhcprsg"
# data = "zcfzfwzzqfrljwzlrfnpqdbhtmscgvjw"

print(data)

for i in range(len(data)-3):
    sub = data[i:i+4]
    if sub.count(sub[0]) > 1:
        continue
    elif sub.count(sub[1]) > 1:
        continue
    elif sub.count(sub[2]) > 1:
        continue
    else:
        print(i+4)
        break