#!/usr/bin/env python3
import sys

if __name__ == '__main__':

    try:
        filename = sys.argv[1]
    except IndexError:
        filename = ""

    if filename == "":
        print("input only digits:")
        seq = input()
        string = str(seq)
    else:
        with open(filename, "r", encoding="utf-8") as file:
            string = file.read(9999).strip()

    total = 0
    length = len(string)

    for i in range(length):
        if (string[i] == string[(i+1)%length]):
            total += int(string[i])

    print(total)