#include <bits/stdc++.h>
using namespace std;

int main() {
    int n;
    cin >> n;

    int a = n / 100;        // 百位
    int b = n / 10 % 10;    // 十位
    int c = n % 10;         // 个位

    int maxNum = a;
    int minNum = a;

    if (b > maxNum) maxNum = b;
    if (c > maxNum) maxNum = c;

    if (b < minNum) minNum = b;
    if (c < minNum) minNum = c;

    cout << maxNum - minNum;
    return 0;
}