#!/usr/bin/env python3

if __name__ == '__main__':
    total = 0
    with open("input", "r", encoding="utf-8") as sheet:
        for line in sheet:
            values = list(map(int, line.split()))
            values.sort()
            value_large = values[-1]
            value_small = values[0]
            difference = value_large - value_small
            total += difference
    print(total)