#!/usr/bin/env python3

import sys

def maximal_distance(A):
    if len(A) == 0:
        return None

    max_n = A[0]
    min_n = A[0]

    for i in range(1,len(A)):
        if max_n < A[i]:
            max_n = A[i]
        elif min_n > A[i]:
            min_n = A[i]

    return max_n - min_n

A = []
for line in sys.stdin:
    if line[0] == '\n':
        break
    A.append(int(line))

print(maximal_distance(A))