#include <bits/stdc++.h>

using namespace std;

#define intl long long
#define LOOPIDX(size) for(int i = 0;i < size;i++)
#define LOOPFROMIDX(begin,size) for(int i = begin;i < size;i++)
#define LOOPIDXREV(size) for(int i = size-1;i >= 0;i--)
#define REP(time) for(int t = 1;t <= time;t++)
#define INPUT(v) cin >> v;
#define PRINT(v) cout << v << endl;
#define PRINTF(v) printf("%.10f\n",v)


template<typename T> T gcd(T x,T y)
{
    if(x == 0 || y == 0) return max(x,y);
    while(true)
    {
        if(x % y == 0) return y;
        auto mod = x % y;
        x = y;
        y = mod;
    }
    return y;
}

int main()
{
    string abc = "";
    cin >> abc;
    string s = "";
    s += abc[0];
    int M = stoi(s);
    int m = stoi(s);
    for(auto s : abc)
    {
        string cs = "";
        cs += s;
        M = max(M,stoi(cs));
        m = min(m,stoi(cs));
    }
    cout << M - m << endl;
    return 0;
}