明天考试，现遇一题不会

#!/usr/bin/python
# -*- coding: UTF-8 -*-
"""
@author: Roc-xb
"""

def func():
    ins = input().split(",")
    print(ins)
    sum = 0.0
    for i in range(len(ins) - 1):
        a = int(ins[i])
        b = int(ins[i + 1])
        a = a + 1 if a <= 0 else a
        b = b + 1 if b <= 0 else b

        if a > b:
            sum += 0.3 * (abs(a - b))
        else:
            sum += abs(a - b)
    print(sum)


if __name__ == '__main__':
    func()