#!/usr/bin/env python3

import sqlite3


def main():
    connection = sqlite3.connect(":memory:")
    cursor = connection.cursor()
    cursor.execute("CREATE TABLE sequence(item INTEGER)")
    n = int(input())
    _ = input()
    xs = ((int(input()), ) for _ in range(n))
    cursor.executemany("INSERT INTO sequence VALUES (?)", xs)
    connection.commit()
    max_x = cursor.execute("SELECT max(item) FROM sequence").fetchone()[0]
    min_x = cursor.execute("SELECT min(item) FROM sequence").fetchone()[0]
    print(max_x - min_x)
    connection.close()


if __name__ == '__main__':
    main()