#include <bits/stdc++.h>

using namespace std;

#define lli long long int
#define REP(i,s,n) for(int i=s;i<n;i++)
#define MOD 1000000007
#define NUM 2520
#define INF (1LL<<50)
#define DEBUG 0
#define mp(a,b) make_pair(a,b)
#define SORT(V) sort(V.begin(),V.end())
#define PI (3.141592653589794)

signed main(){

	lli a,b,c;
	cin>>a>>b>>c;

	if(c>a)swap(a,b);
	if(a==c){
		cout<<0<<endl;
		return 0;
	}

	lli ans = INF;
	if(a<b){
		ans = min(ans,b-a+1);
		ans = min(ans,a-c);
	}
	else{
		cout<<0<<endl;
	}

	return 0;
}